modelverse/core/core_algorithm.alc

include "modelling.alh"
include "library.alh"
include "primitives.alh"
include "constructors.alh"
include "object_operations.alh"
include "mini_modify.alh"
include "model_management.alh"
include "ramify.alh"
include "conformance_scd.alh"
include "transform.alh"
include "metamodels.alh"

Element core = ?

String core_location = "models/CoreFormalism"
String core_model_location = "core"

String function JSON_print(model : Element):
	String result
	Element keys_m
	String v_m
	String type
	String attr_key
	Element attr_keys
	Boolean first
	Element attr_value

	result = "["
	keys_m = dict_keys(model["model"])
	first = True

	while (read_nr_out(keys_m) > 0):
		v_m = set_pop(keys_m)
		type = read_type(model["metamodel"], read_type(model, v_m))

		if (bool_or(type == "Class", type == "Association")):
			if (bool_not(first)):
				result = result + ","
			else:
				first = False

			result = result + "{"
			result = (((result + "\"id\": \"") + v_m) + "\"")
			result = (((result + ",") + "\"type\": \"") + read_type(model, v_m)) + "\""
			if (type == "Association"):
				result = (((result + ", \"__source\": \"") + reverseKeyLookup(model["model"], read_edge_src(model["model"][v_m]))) + "\"")
				result = (((result + ", \"__target\": \"") + reverseKeyLookup(model["model"], read_edge_dst(model["model"][v_m]))) + "\"")

			// Has attributes
			attr_keys = dict_keys(getAttributeList(model, v_m))
			while (0 < read_nr_out(attr_keys)):
				attr_key = set_pop(attr_keys)
				attr_value = read_attribute(model, v_m, attr_key)
				if (element_eq(attr_value, read_root())):
					result = (((result + ", \"") + attr_key) + "\": null")
				else:
					if (is_physical_boolean(attr_value)):
						if (attr_value):
							result = ((result + ", \"") + attr_key) + "\": true"
						else:
							result = ((result + ", \"") + attr_key) + "\": false"
					else:
						result = ((((result + ", \"") + attr_key) + "\": ") + cast_v2s(attr_value))

			result = result + "}"

	result = result + "]"

	return result!

Void function main():
	// Initialize the Core Formalism
	String core_model
	String core_formalism_model
	String scd_model
	Element al_model
	String admin_group
	String admin_user
	String nobody_group
	String instance_of
	String core_formalism
	Element scd
	Element al
	Element pm
	Element tracability
	String pm_model
	String tracability_model
	String coreM_model_location 
	String pm_location
	String scd_location
	String al_location
	String tracability_location

	coreM_model_location = "models/core"
	pm_location = "models/ProcessModel"
	scd_location = "models/SimpleClassDiagrams"
	al_location = "models/ActionLanguage"
	tracability_location = "models/Tracability"

	scd = import_node(scd_location)
	al = import_node(al_location)
	pm = import_node(pm_location)
	tracability = import_node(tracability_location)

	// Create the Model itself and make public
	core_formalism = import_node(core_location)
	core = instantiate_model(core_formalism)
	export_node(core_model_location, core)
	export_node(coreM_model_location, core["model"])

	// Switch all new users to the user_function
	// This accesses the bootstrap level, so do not change this unless you know what you are doing
	Element root
	Element prev
	root = read_root()
	root = root["__hierarchy"]["__IP"]
	while (value_neq(root, !call)):
		prev = root
		root = root["next"]
	dict_delete(prev, "next")
	dict_add(prev, "next", user_function["body"])

	// Create admin group
	admin_group = instantiate_node(core, "Group", "")
	instantiate_attribute(core, admin_group, "name", "admin")

	// Create nobody group
	nobody_group = instantiate_node(core, "Group", "")
	instantiate_attribute(core, nobody_group, "name", "nobody")

	// Create admin user
	admin_user = instantiate_node(core, "User", "")
	output("Desired username for admin user?")
	instantiate_attribute(core, admin_user, "name", input())
	instantiate_attribute(core, admin_user, "admin", True)

	String password

	while (True):
		output("Desired password for admin user?")
		password = hash(input())

		output("Please repeat the password")
		if (password == hash(input())):
			output("Passwords match!")
			instantiate_attribute(core, admin_user, "password", password)
			break!
		else:
			output("Not the same password, please try again!")

	// Create link between admin user and group
	instantiate_link(core, "ownedBy", "", admin_group, admin_user)
	instantiate_link(core, "belongsTo", "", admin_user, admin_group)

	// Add the SimpleClassDiagrams formalism already
	scd_model = instantiate_node(core, "Model", "")
	instantiate_attribute(core, scd_model, "name", "SimpleClassDiagrams")
	instantiate_attribute(core, scd_model, "location", scd_location + "/model")
	instantiate_attribute(core, scd_model, "permissions", "221")
	instance_of = instantiate_link(core, "instanceOf", "", scd_model, scd_model)
	instantiate_attribute(core, instance_of, "type_mapping", scd["type_mapping"])

	// Make necessary links for the formalism to the owners
	instantiate_link(core, "group", "", scd_model, admin_group)
	instantiate_link(core, "owner", "", scd_model, admin_user)

	// Add the Tracability formalism
	tracability_model = instantiate_node(core, "Model", "")
	instantiate_attribute(core, tracability_model, "name", "Tracability")
	instantiate_attribute(core, tracability_model, "location", tracability_location + "/model")
	instantiate_attribute(core, tracability_model, "permissions", "221")
	instance_of = instantiate_link(core, "instanceOf", "", tracability_model, scd_model)
	instantiate_attribute(core, instance_of, "type_mapping", tracability["type_mapping"])

	// Add the user/group links
	instantiate_link(core, "group", "", tracability_model, admin_group)
	instantiate_link(core, "owner", "", tracability_model, admin_user)

	// Add the Process Model formalism
	pm_model = instantiate_node(core, "Model", "")
	instantiate_attribute(core, pm_model, "name", "ProcessModel")
	instantiate_attribute(core, pm_model, "location", pm_location + "/model")
	instantiate_attribute(core, pm_model, "permissions", "221")
	instance_of = instantiate_link(core, "instanceOf", "", pm_model, scd_model)
	instantiate_attribute(core, instance_of, "type_mapping", pm["type_mapping"])

	// Make necessary links for the formalism to the owners
	instantiate_link(core, "group", "", pm_model, admin_group)
	instantiate_link(core, "owner", "", pm_model, admin_user)

	// Add the Action Language formalism
	al_model = instantiate_node(core, "Model", "")
	instantiate_attribute(core, al_model, "name", "ActionLanguage")
	instantiate_attribute(core, al_model, "location", al_location + "/model")
	instantiate_attribute(core, al_model, "permissions", "221")
	instance_of = instantiate_link(core, "instanceOf", "", al_model, scd_model)
	instantiate_attribute(core, instance_of, "type_mapping", al["type_mapping"])

	// Make necessary links for the formalism to the owners
	instantiate_link(core, "group", "", al_model, admin_group)
	instantiate_link(core, "owner", "", al_model, admin_user)

	// Add the Manual Operation formalism
	Element manual
	String manual_model
	manual = instantiate_model(scd)
	manual_model = instantiate_node(core, "Model", "")
	export_node("models/ManualOperation", manual)
	instantiate_attribute(core, manual_model, "name", "ManualOperation")
	instantiate_attribute(core, manual_model, "location", "models/ManualOperation/model")
	instantiate_attribute(core, manual_model, "permissions", "221")
	instance_of = instantiate_link(core, "instanceOf", "", manual_model, scd_model)
	instantiate_attribute(core, instance_of, "type_mapping", create_node())

	// Make necessary links for the formalism to the owners
	instantiate_link(core, "group", "", manual_model, admin_group)
	instantiate_link(core, "owner", "", manual_model, admin_user)

	// Add the core formalism already
	core_formalism_model = instantiate_node(core, "Model", "")
	instantiate_attribute(core, core_formalism_model, "name", "CoreFormalism")
	instantiate_attribute(core, core_formalism_model, "location", core_location + "/model")
	instantiate_attribute(core, core_formalism_model, "permissions", "221")
	instance_of = instantiate_link(core, "instanceOf", "", core_formalism_model, scd_model)
	instantiate_attribute(core, instance_of, "type_mapping", core_formalism["type_mapping"])

	// Make necessary links for the formalism to the owners
	instantiate_link(core, "group", "", core_formalism_model, admin_group)
	instantiate_link(core, "owner", "", core_formalism_model, admin_user)

	// Add the core model
	core_model = instantiate_node(core, "Model", "")
	instantiate_attribute(core, core_model, "name", "core")
	instantiate_attribute(core, core_model, "location", coreM_model_location)
	instantiate_attribute(core, core_model, "permissions", "200")
	instance_of = instantiate_link(core, "instanceOf", "", core_model, core_formalism_model)
	instantiate_attribute(core, instance_of, "type_mapping", core["type_mapping"])

	// Make necessary links for the formalism to the owners
	instantiate_link(core, "group", "", core_model, admin_group)
	instantiate_link(core, "owner", "", core_model, admin_user)

	// Call this for ourselves as well
	log("MvC is ready!")
	user_function_skip_init(admin_user)

	// Done, so finish up
	// Admin user will have been deleted by the user_function as usual
	// Note that if there are no admin users left, it will be very difficult to manage, as nobody will have admin permissions!
	return !

String function get_instanceOf_link(model_id : String):
	Element all_links
	String choice

	all_links = allOutgoingAssociationInstances(core, model_id, "instanceOf")

	if (read_nr_out(all_links) > 1):
		log("WARNING: multiple instanceOf relations were detected for this model; picking one at random!")
	elif (read_nr_out(all_links) == 0):
		log("ERROR: untyped model!")
	
	choice = set_pop(allOutgoingAssociationInstances(core, model_id, "instanceOf"))

	return choice!

Element function get_full_model(model_id : String):
	Element m
	Element all_links
	String choice

	choice = get_instanceOf_link(model_id)

	m = create_node()
	dict_add(m, "model", import_node(read_attribute(core, model_id, "location")))
	dict_add(m, "type_mapping", read_attribute(core, choice, "type_mapping"))

	if (readAssociationDestination(core, choice) == model_id):
		// Found the meta-circular level, so we can stop!
		dict_add(m, "metamodel", m)
	else:
		dict_add(m, "metamodel", get_full_model(readAssociationDestination(core, choice)))
		
	return m!

Integer function get_relation_to_model(user_id : String, model_id : String):
	if (set_in(allAssociationDestinations(core, model_id, "owner"), user_id)):
		// We are the owner
		return 0!
	else:
		String group_id
		group_id = set_pop(allAssociationDestinations(core, model_id, "group"))
		if (set_in(allAssociationDestinations(core, user_id, "belongsTo"), group_id)):
			// We are in the owning group
			return 1!
		else:
			// We are not related whatsoever
			return 2!

Boolean function is_admin(user_id : String):
	if (read_attribute(core, user_id, "admin")):
		return True!
	else:
		return False!
	
Boolean function allow_read(user_id : String, model_id : String):
	if (is_admin(user_id)):
		// Is admin, so always allow
		return True!
	else:
		// Check permissions
		String permission
		permission = string_get(read_attribute(core, model_id, "permissions"), get_relation_to_model(user_id, model_id))
		if (bool_or(permission == "1", permission == "2")):
			return True!
		else:
			return False!

Boolean function allow_write(user_id : String, model_id : String):
	if (is_admin(user_id)):
		// Is admin, so always allow
		return True!
	else:
		// Check permissions
		String permission
		permission = string_get(read_attribute(core, model_id, "permissions"), get_relation_to_model(user_id, model_id))
		if (permission == "2"):
			return True!
		else:
			return False!

Boolean function allow_change_metadata(user_id : String, model_id : String):
	if (is_admin(user_id)):
		// Is admin, so always allow
		return True!
	else:
		if (get_relation_to_model(user_id, model_id) == 0):
			// Only owner can chmod
			return True!
		else:
			return False!

Boolean function allow_group_modify(user_id : String, group_id : String):
	if (is_admin(user_id)):
		// Is admin, so always allow
		return True!
	else:
		if (read_nr_out(set_overlap(allIncomingAssociationInstances(core, user_id, "owner"), allOutgoingAssociationInstances(core, group_id, "owner"))) > 0):
			// We are an owner
			return True!
		else:
			return False!

Boolean function check_login(user_id : String):
	String password
	String stored_password

	stored_password = read_attribute(core, user_id, "password")

	output("Password for existing user?")
	password = hash(input())

	return password == stored_password!

Element function extract_ftg(user_id : String):
	// Extract your personal FTG, showing only the readable models that can be opened
	// This function does the actual projection of transformations

	// TODO: Only keep transformations satisfying some properties!

	return create_node()!

Element function user_function():
	String username
	String user_id
	String password

	// Load in all global variables, as this code is hotloaded!
	Element root
	root = read_root()
	root = root["__hierarchy"]["objects"]
	exec(root["bootstrap/modelling.alc"]["initializers"])
	exec(root["bootstrap/library.alc"]["initializers"])
	exec(root["bootstrap/constructors.alc"]["initializers"])
	exec(root["bootstrap/object_operations.alc"]["initializers"])
	exec(root["core/mini_modify.alc"]["initializers"])
	exec(root["bootstrap/model_management.alc"]["initializers"])
	exec(root["bootstrap/ramify.alc"]["initializers"])
	exec(root["bootstrap/transform.alc"]["initializers"])
	exec(root["bootstrap/conformance_scd.alc"]["initializers"])
	exec(root["bootstrap/metamodels.alc"]["initializers"])
	exec(root["core/core_algorithm.alc"]["initializers"])

	// Load in a hard-reference to the previously created model
	core = import_node(core_model_location)

	while (True):
		output("Log on as which user?")
		username = input()

		user_id = get_user_id(username)
		if (user_id == ""):
			// New user
			// Add user to Core Formalism
			user_id = instantiate_node(core, "User", "")
			instantiate_attribute(core, user_id, "name", username)
			instantiate_attribute(core, user_id, "admin", False)

			output("This is a new user: please give password!")
			password = hash(input())

			output("Please repeat the password")
			if (password == hash(input())):
				output("Passwords match!")
				instantiate_attribute(core, user_id, "password", password)
				break!
			else:
				output("Not the same password!")
		else:
			if (check_login(user_id)):
				break!
			else:
				output("Wrong password!")

	user_function_skip_init(user_id)

	// User destroyed already, so just stop execution
	// TODO return a fresh node as otherwise the compiler doesn't take this
	return create_node()!

String function get_model_id(name : String):
	Element models
	String model

	models = allInstances(core, "Model")
	while (read_nr_out(models) > 0):
		model = set_pop(models)
		if (value_eq(name, read_attribute(core, model, "name"))):
			return model!
	
	return ""!

String function get_user_id(name : String):
	Element users
	String user

	users = allInstances(core, "User")

	while (read_nr_out(users) > 0):
		user = set_pop(users)
		if (value_eq(read_attribute(core, user, "name"), name)):
			return user!
	
	return ""!

String function get_group_id(name : String):
	Element groups
	String group

	groups = allInstances(core, "Group")
	while (read_nr_out(groups) > 0):
		group = set_pop(groups)
		if (value_eq(read_attribute(core, group, "name"), name)):
			return group!
	
	return ""!

Void function model_create(model : Element, name : String, user_id : String, type_id : String, kind : String):
	String location
	String model_id
	String instance_of

	location = "models/" + cast_id2s(model)
	export_node(location, model["model"])

	// Manage meta-info
	model_id = instantiate_node(core, kind, "")
	instantiate_attribute(core, model_id, "name", name)
	instantiate_attribute(core, model_id, "location", location)
	instantiate_attribute(core, model_id, "permissions", "200")
	instantiate_link(core, "owner", "", model_id, user_id)
	instantiate_link(core, "group", "", model_id, get_group_id("nobody"))
	instance_of = instantiate_link(core, "instanceOf", "", model_id, type_id)
	instantiate_attribute(core, instance_of, "type_mapping", model["type_mapping"])

	return!

Void function model_overwrite(model : Element, model_id : String):
	String location
	String instanceOf_link

	location = "models/" + cast_id2s(model)
	export_node(location, model["model"])

	// Change location in meta-data
	unset_attribute(core, model_id, "location")
	instantiate_attribute(core, model_id, "location", location)

	instanceOf_link = get_instanceOf_link(model_id)
	unset_attribute(core, instanceOf_link, "type_mapping")
	instantiate_attribute(core, instanceOf_link, "type_mapping", model["type_mapping"])

	return!

Boolean function check_is_typed_by(model_id : String, metamodel_id : String):
	// TODO check if there is actually an instanceOf link between them
	//    --> quick check!

	return True!

Boolean function check_conformance(model_id : String):
	// TODO check if it actually conforms, considering that instanceOf link
	//    --> in-depth check

	return True!

Boolean function pm_finished(worklist : Element, pm : String):
	Element finished
	Integer cnt
	Integer i

	// Check if any of the "finish" elements are in the worklist
	// If so, we can already finish, and therefore will stop immediately
	finished = allInstances(pm, "Finish")
	i = 0
	cnt = read_nr_out(finished)

	while (i < cnt):
		// Check each finished element individually
		if (set_in(finished, dict_read(read_edge_dst(read_out(worklist, i)), 0))):
			return True!
		i = i + 1

	return False!

Element function execute_operation(operation_id : String, input_models : Element, output_metamodels : Element, tracability_model : Element):
	// Operations are always in-place and uses only a single metamodel
	// Therefore, we must:
	//		1) Find merged metamodel
	// 		2) Merge the different source models and retype
	//		3) Perform the operation on the merged model
	//		4) Split the resulting model based on the target formalisms; if operation successful
	
	Element input_model
	String trace_link_id
	Element merged_model
	String merged_metamodel_id
	String ramified_metamodel_id
	Boolean result
	String exact_type
	Element trace_links
	String linktype
	String model_ID
	String key
	Element keys
	Element input_keys
	Element output_keys
	Element model_tuples
	String metamodel_name
	Element metamodel
	String metamodel_ID
	Boolean tracability

	// 1) Find merged metamodel

	exact_type = read_type(core, operation_id)

	if (exact_type == "ModelTransformation"):
		linktype = "RAMified"
		ramified_metamodel_id = set_pop(allAssociationDestinations(core, operation_id, "instanceOf"))
		trace_links = allOutgoingAssociationInstances(core, ramified_metamodel_id, "tracability")
	elif (exact_type == "ManualOperation"):
		linktype = "operatesOn"
		trace_links = allOutgoingAssociationInstances(core, operation_id, "tracability")
	elif (exact_type == "ActionLanguage"):
		linktype = "operatesOn"
		trace_links = allOutgoingAssociationInstances(core, operation_id, "tracability")
	else:
		// Don't know how to execute this operation!
		return read_root()!

	merged_metamodel_id = ""
	while (read_nr_out(trace_links) > 0):
		trace_link_id = set_pop(trace_links)
		if (value_eq(read_attribute(core, trace_link_id, "type"), linktype)):
			merged_metamodel_id = readAssociationDestination(core, trace_link_id)

	if (merged_metamodel_id != ""):
		// 2) Merge source models

		model_tuples = create_node()
		while (read_nr_out(input_models) > 0):
			model_ID = get_model_id(set_pop(input_models))
			input_model = get_full_model(model_ID)
			metamodel_name = read_attribute(core, set_pop(allAssociationDestinations(core, model_ID, "instanceOf")), "name")
			set_add(model_tuples, create_tuple(metamodel_name, input_model))

		merged_model = model_join(model_tuples, get_full_model(merged_metamodel_id), tracability_model)

		// 3) Transform

		if (exact_type == "ModelTransformation"):
			result = transform(merged_model, get_full_model(operation_id))
		elif (exact_type == "ManualOperation"):
			output("Please perform manual operation " + cast_v2s(read_attribute(core, operation_id, "name")))
			modify(merged_model, True)
			result = True
		elif (exact_type == "ActionLanguage"):
			Element func
			func = get_func_AL_model(get_full_model(operation_id))
			result = func(merged_model)
		else:
			log("ERROR")

		// 4) Split in different models depending on type

		if (element_neq(tracability_model, read_root())):
			tracability = True
		else:
			tracability = False

		if (result):
			model_tuples = create_node()
			while (read_nr_out(output_metamodels) > 0):
				metamodel_ID = get_model_id(set_pop(output_metamodels))
				metamodel_name = read_attribute(core, metamodel_ID, "name")
				metamodel = get_full_model(metamodel_ID)
				set_add(model_tuples, create_tuple(metamodel_name, metamodel))

			result = model_split(merged_model, model_tuples, tracability)

			if (tracability):
				Element new_tracability_model
				new_tracability_model = result["__tracability"]
				dict_overwrite(tracability_model, "model", new_tracability_model["model"])
				dict_overwrite(tracability_model, "type_mapping", new_tracability_model["type_mapping"])
				dict_overwrite(tracability_model, "metamodel", new_tracability_model["metamodel"])
				dict_delete(result, "__tracability")

			return result!
		else:
			return read_root()!

	else:
		output("Could not resolve intermediate merged metamodel")
		return read_root()!

Boolean function enact_action(pm : Element, element : String, prefix : String, user_id : String):
	Boolean result
	String transformation_id
	Element lst
	String elem
	Element inputs
	Element outputs
	String type_name
	String exact_type
	Element trace_links
	Element output_mms
	Element consumes_link
	String name
	String value
	String elem_name
	Element keys
	String key

	inputs = create_node()
	outputs = create_node()

	// Read out the referenced element from the MvC
	transformation_id = get_model_id(read_attribute(pm, element, "name"))

	// Find all input model names
	lst = allOutgoingAssociationInstances(pm, element, "Consumes")
	while (read_nr_out(lst) > 0):
		value = read_attribute(pm, readAssociationDestination(pm, set_pop(lst)), "name")
		set_add(inputs, prefix + value)

	// Find all output model names and their metamodel
	lst = allAssociationDestinations(pm, element, "Produces")
	while (read_nr_out(lst) > 0):
		elem = set_pop(lst)
		type_name = read_attribute(pm, elem, "type")
		elem_name = read_attribute(pm, elem, "name")
		dict_add(outputs, type_name, prefix + elem_name)

	result = execute_operation(transformation_id, inputs, dict_keys(outputs), read_root())

	if (element_eq(result, read_root())):
		// Something went wrong!
		return False!
	else:
		keys = dict_keys(result)
		while (read_nr_out(keys) > 0):
			key = set_pop(keys)
			if (get_model_id(outputs[key]) == ""):
				// New model
				model_create(result[key], outputs[key], user_id, get_model_id(key), "Model")
			else:
				model_overwrite(result[key], get_model_id(outputs[key]))
		return True!

Void function enact_PM(pm : Element, prefix : String, user_id : String):
	Element worklist
	String element
	String start
	String type
	Boolean result
	Element tuple
	Element counters
	Element join_nodes

	// Initialize Join counters
	counters = create_node()
	join_nodes = allInstances(pm, "Join")
	while (read_nr_out(join_nodes) > 0):
		dict_add(counters, set_pop(join_nodes), 0)

	// Create the worklist with the Start instance as first element
	worklist = create_node()
	set_add(worklist, create_tuple(set_pop(allInstances(pm, "Start")), True))

	while (bool_not(pm_finished(worklist, pm))):
		// Pop a random element from the list and execute it
		tuple = set_pop(worklist)
		element = tuple[0]
		result = tuple[1]

		log("Enacting " + cast_v2s(element))

		// Find the type (to see what to do with it)
		//   this does not yet yield the type of transformation, if it is an Execution
		type = read_type(pm, element)

		if (type == "Start"):
			// Initial node, just progress to the next elements
			// Nothing to do here though, as we have just started
			result = True
		elif (type == "Finish"):
			// Should be impossible, as we would have ended...
			result = result
		elif (type == "Fork"):
			result = result
		elif (type == "Join"):
			// Only do this if all dependencies are fullfilled
			// So add to the counter of this Join
			dict_overwrite(counters, element, integer_addition(counters[element], 1))

			// Now check whether we have enough tokens to execute the Join itself
			Integer required
			Integer got
			required = read_nr_out(allIncomingAssociationInstances(pm, element, "Next")) + read_nr_out(allIncomingAssociationInstances(pm, element, "Else"))
			got = counters[element]
			if (got == required):
				// Reset counter to 0
				dict_overwrite(counters, element, 0)

				// And continue
			else:
				// We haven't gotten all yet, so we wait (i.e., continue without adding Next link to worklist)
				continue!

		elif (type == "Exec"):
			// Execute a transformation
			// This the difficult part!

			result = enact_action(pm, element, prefix, user_id)

		elif (type == "Decision"):
			// If the previous result is true, we add the normal one, otherwise the false one
			// in this context, that means that if it is false, we should add it manually to the list, and then continue the simulation loop
			if (bool_not(result)):
				// Apparently it is False, so map this to the "Else" branch
				set_add(worklist, create_tuple(set_pop(allAssociationDestinations(pm, element, "Else")), True))
				continue!
			else:
				// Apparently it is True, so map this to the "Then" branch
				set_add(worklist, create_tuple(set_pop(allAssociationDestinations(pm, element, "Then")), True))
				continue!

		// We have finished the execution, so add all outgoing edges to the worklist
		Element all_next
		all_next = allAssociationDestinations(pm, element, "Next")
		String next
		while (read_nr_out(all_next) > 0):
			next = set_pop(all_next)
			set_add(worklist, create_tuple(next, result))

	// Reached a finish element, so stop
	return !

String function cmd_help(user_id : String):
	String result

	result = ""
	result = result + ("Model operations\n")
	result = result + ("    model_add                       -- Add a new model\n")
	result = result + ("    model_modify                    -- Modify an existing model\n")
	result = result + ("    model_list                      -- List all models\n")
	result = result + ("    model_list_full                 -- List all models with full info\n")
	result = result + ("    model_overwrite                 -- Overwrites a model with an uploaded model, leaving all metadata\n")
	result = result + ("    model_render                    -- Render a given model with a specified mapper\n")
	result = result + ("    verify                          -- Check whether a model conforms to its metamodel\n")
	result = result + ("\n")
	result = result + ("Transformation-specific operations\n")
	result = result + ("    transformation_add_MT_language  -- Create a RAMified metamodel of a set of models\n")
	result = result + ("    transformation_add_MT           -- Initialize a new model transformation\n")
	result = result + ("    transformation_add_AL           -- Initialize a new action language transformation\n")
	result = result + ("    transformation_add_MANUAL       -- Initialize a new manual transformation\n")
	result = result + ("    transformation_execute          -- Execute a transformation on a set of input models\n")
	result = result + ("    transformation_list             -- List all model transformations\n")
	result = result + ("    transformation_list_full        -- List all model transformations with permissions\n")
	result = result + ("    transformation_detail           -- List transformation details\n")
	result = result + ("    transformation_RAMify           -- RAMify a metamodel (again)\n")
	result = result + ("    transformation_between          -- List all transformations between two metamodels\n")
	result = result + ("\n")
	result = result + ("Process operations\n")
	result = result + ("    process_execute                 -- Execute a process model\n")
	result = result + ("\n")
	result = result + ("Model permission operations\n")
	result = result + ("    permission_modify               -- Change model permissions\n")
	result = result + ("    permission_owner                -- Change model owner\n")
	result = result + ("    permission_group                -- Change model group\n")
	result = result + ("\n")
	result = result + ("Group operations\n")
	result = result + ("    group_create                    -- Create a group\n")
	result = result + ("    group_delete                    -- Delete a group\n")
	result = result + ("    group_owner_add                 -- Add group owner\n")
	result = result + ("    group_owner_delete              -- Remove group owner\n")
	result = result + ("    group_join                      -- Add someone to your group\n")
	result = result + ("    group_kick                      -- Kick someone from your group\n")
	result = result + ("    group_list                      -- List all groups you are a member of\n")
	result = result + ("\n")

	if (is_admin(user_id)):
		result = result + ("Admin operations\n")
		result = result + ("    admin_promote                   -- Promote a user to admin status\n")
		result = result + ("    admin_demote                    -- Demote a user to normal status\n")
		result = result + ("\n")

	result = result + ("General operations\n")
	result = result + ("    self-destruct                   -- Remove current user and revoke all permissions \n")
	result = result + ("    exit                            -- Kill the current task, while retaining user\n")

	return result!

String function cmd_model_add(user_id : String, type : String, name : String):
	// Model addition operation, which uses model upload commands of the compiler
	String location
	String type_id
	Element new_model
	String new_model_id

	type_id = get_model_id(type)
	if (type_id != ""):
		// Type exists
		if (allow_read(user_id, type_id)):
			// And is readable
			if (get_model_id(name) == ""):
				// Model doesn't exist yet
				output("Waiting for model constructors...")
				new_model = construct_model_raw(get_full_model(type_id))
				model_create(new_model, name, user_id, type_id, "Model")
				return "Success"!
			else:
				return "Model exists: " + name!
		else:
			return "Permission denied to model: " + type!
	else:
		return "Model not found: " + type!

String function cmd_process_execute(user_id : String, process : String, prefix : String):
	// Execute a process model until it reaches termination
	String process_id

	process_id = get_model_id(process)
	if (process_id != ""):
		if (allow_read(user_id, process_id)):
			enact_PM(get_full_model(process_id), prefix, user_id)
			return "Success"!
		else:
			return "Permission denied to model: " + process!
	else:
		return "Model not found: " + process!

String function cmd_transformation_between(user_id : String, source_name : String, target_name : String):
	String source_id
	String target_id
	Element onSource
	Element onTarget
	Element result
	String transformation

	source_id = get_model_id(source_name)
	if (source_id != ""):
		target_id = get_model_id(target_name)

		if (target_id != ""):
			onSource = allAssociationOrigins(core, source_id, "transformInput")
			onTarget = allAssociationOrigins(core, target_id, "transformOutput")

			result = set_overlap(onSource, onTarget)

			String r
			r = "Success: "
			while (read_nr_out(result) > 0):
				transformation = set_pop(result)
				if (allow_read(user_id, transformation)):
					r = r + string_join(read_attribute(core, transformation, "name"), "\n")
			return r!
		else:
			return "Model not found: " + target_name!
	else:
		return "Model not found: " + source_name!

String function cmd_model_render(user_id : String, model_name : String, mapper_name : String):
	String model_ID
	String mapper_ID
	String rendered_name
	String tracability_name
	String type_ID
	Element inputs
	Element outputs
	Element rendered_model
	Element tracability_model
	Element result
	Element out_links
	Element in_links

	model_ID = get_model_id(model_name)

	if (model_ID != ""):
		mapper_ID = get_model_id(mapper_name)

		if (allow_read(user_id, model_ID)):
			if (mapper_ID != ""):
				if (allow_read(user_id, mapper_ID)):
					// Everything is fine; start the actual operation
					// Find metamodel to render to
					rendered_name = (("__RENDERED_" + model_name) + "__") + mapper_name
					tracability_name = (("__TRACABILITY_" + model_name) + "__") + mapper_name

					// Take the abstract syntax model and the previously rendered model
					inputs = create_node()
					set_add(inputs, model_name)
					set_add(inputs, rendered_name)

					// Generate a new rendered model only (no write to original model!)
					outputs = create_node()
					out_links = allAssociationDestinations(core, mapper_ID, "transformOutput")
					in_links = allAssociationDestinations(core, mapper_ID, "transformInput")
					while(read_nr_out(out_links) > 0):
						type_ID = set_pop(out_links)
						if (bool_not(set_in(in_links, type_ID))):
							// It is not the AS model, but another one (the MM_rendered)
							break!

					// Add the model itself as output as well, as otherwise tracability links get messed up!
					set_add(outputs, read_attribute(core, set_pop(allAssociationDestinations(core, get_model_id(model_name), "instanceOf")), "name"))
					set_add(outputs, read_attribute(core, type_ID, "name"))

					// Rendered model doesn't exist yet, so create first
					if (get_model_id(rendered_name) == ""):
						// Rendered model doesn't exist yet, so create first!
						rendered_model = instantiate_model(get_full_model(type_ID))
						model_create(rendered_model, rendered_name, user_id, type_ID, "Model")
						
						// Tracability model won't exist either
						tracability_model = instantiate_model(get_full_model(get_model_id("Tracability")))
						model_create(tracability_model, tracability_name, user_id, get_model_id("Tracability"), "Model")

					else:
						// Read out tracability model
						tracability_model = get_full_model(get_model_id(tracability_name))

					// Do the operation itself!
					result = execute_operation(mapper_ID, inputs, outputs, tracability_model)

					// Overwrite the previous rendered model
					model_overwrite(result[read_attribute(core, type_ID, "name")], get_model_id(rendered_name))

					// Tracability updated in-place
					model_overwrite(tracability_model, get_model_id(tracability_name))
					tracability_model = get_full_model(get_model_id(tracability_name))

					// Also output the resulting model
					return "Success: " + JSON_print(get_full_model(get_model_id(rendered_name)))!
				else:
					return "Permission denied to model: " + mapper_name!
			else:
				return "Model not found: " + mapper_name!
		else:
			return "Permission denied to model: " + model_name!
	else:
		return "Model not found: " + model_name!

String function cmd_transformation_execute(user_id : String, transformation_name : String, source_models : Element, target_models : Element):
	// Execute a transformation, whatever type it is
	// First we detect the type, so we know how to prepare for invocation
	String transformation_id
	String exact_type
	Element sources
	Element targets
	String source
	String target
	Element inputs
	Element outputs
	Element trace_links
	String target_model_name
	String source_model_name
	String source_model_ID
	Element result
	Element keys
	String key

	transformation_id = get_model_id(transformation_name)
	if (transformation_id != ""):
		if (allow_read(user_id, transformation_id)):
			if (is_nominal_instance(core, transformation_id, "Transformation")):
				// Read out source and target links
				inputs = create_node()

				sources = allOutgoingAssociationInstances(core, transformation_id, "transformInput")
				while (read_nr_out(sources) > 0):
					source = set_pop(sources)
					if (dict_in(source_models, read_attribute(core, readAssociationDestination(core, source), "name"))):
						source_model_name = source_models[read_attribute(core, readAssociationDestination(core, source), "name")]
					else:
						return string_join("Source model not bound: ", read_attribute(core, readAssociationDestination(core, source), "name"))!

					source_model_ID = get_model_id(source_model_name)
					if (source_model_ID != ""):
						if (allow_read(user_id, source_model_ID)):
							// Check for conformance to the requested metamodel
							if (check_is_typed_by(source_model_ID, source)):
								if (check_conformance(source_model_ID)):
									set_add(inputs, source_model_name)
									continue!
								else:
									return "Incorrectly typed model: " + source_model_name!
							else:
								return "Incorrectly typed model: " + source_model_name!
						else:
							return "Permission denied to model: " + source_model_name!
					else:
						return "Model not found: " + source_model_name!

				targets = allOutgoingAssociationInstances(core, transformation_id, "transformOutput")
				outputs = create_node()
				while (read_nr_out(targets) > 0):
					target = set_pop(targets)
					if (dict_in(target_models, read_attribute(core, readAssociationDestination(core, target), "name"))):
						target_model_name = target_models[read_attribute(core, readAssociationDestination(core, target), "name")]
					else:
						return string_join("Target model not bound: ", read_attribute(core, readAssociationDestination(core, target), "name"))!

					if (get_model_id(target_model_name) == ""):
						// Doesn't exist yet, so we can easily create
						dict_add(outputs, read_attribute(core, readAssociationDestination(core, target), "name"), target_model_name)
					else:
						// Already exists, so we need to check for write access
						if (allow_write(user_id, get_model_id(target_model_name))):
							dict_add(outputs, read_attribute(core, readAssociationDestination(core, target), "name"), target_model_name)
						else:
							return "Permission denied to model: " + target_model_name!

				if (read_type(core, transformation_id) == "ActionLanguage"):
					output("Success: ready for AL execution")
				elif (read_type(core, transformation_id) == "ManualOperation"):
					output("Success: ready for MANUAL execution")
				else:
					output("Success: ready for MT execution")

				result = execute_operation(transformation_id, inputs, dict_keys(outputs), read_root())

				// Now write out the models again
				if (element_eq(result, read_root())):
					// Something went wrong!
					return "Failure"!
				else:
					keys = dict_keys(result)
					while (read_nr_out(keys) > 0):
						key = set_pop(keys)
						
						if (get_model_id(outputs[key]) == ""):
							// New model
							model_create(result[key], outputs[key], user_id, get_model_id(key), "Model")
						else:
							model_overwrite(result[key], get_model_id(outputs[key]))

					return "Success"!
			else:
				return "Model is not executable: " + transformation_name!
		else:
			return "Permission denied to model: " + transformation_name!
	else:
		return "Model not found: " + transformation_name!

String function cmd_verify(user_id : String, model_name : String):
	// Check whether a model conforms to its specification (with the selected type mapping)
	String model_id
	String result

	model_id = get_model_id(model_name)
	if (model_id != ""):
		if (allow_read(user_id, model_id)):
			result = conformance_scd(get_full_model(model_id))
			return "Success: " + result!
		else:
			return "Permission denied to model: " + model_name!
	else:
		return "Model not found: " + model_name!

String function cmd_model_overwrite(user_id : String, model_name : String):
	// Overwrites an existing model without changing any metadata
	String model_id
	String type_id
	Element new_model

	model_id = get_model_id(model_name)
	if (model_id != ""):
		if (allow_write(user_id, model_id)):
			type_id = set_pop(allAssociationDestinations(core, model_id, "instanceOf"))
			if (allow_read(user_id, type_id)):
				output("Waiting for model constructors...")
				new_model = construct_model_raw(get_full_model(set_pop(allAssociationDestinations(core, model_id, "instanceOf"))))
				model_overwrite(new_model, model_id)
				return "Success"!
			else:
				return string_join("Permission denied to model: ", read_attribute(core, type_id, "name"))!
		else:
			return "Permission denied to model: " + model_name!
	else:
		return "Model not found: " + model_name!

String function cmd_model_modify(user_id : String, model_name : String):
	// Model modify operation, which uses the mini_modify.alc operations, though with extensions for access control
	String model_id
	String type_id

	model_id = get_model_id(model_name)

	if (model_id != ""):
		if (allow_read(user_id, model_id)):
			type_id = set_pop(allAssociationDestinations(core, model_id, "instanceOf"))
			if (allow_read(user_id, type_id)):
				output("Success")
				modify(get_full_model(model_id), allow_write(user_id, model_id))
				return "Success"!
			else:
				return string_join("Permission denied to model: ", read_attribute(core, type_id, "name"))!
		else:
			return "Permission denied to model: " + model_name!
	else:
		return "Model not found: " + model_name!

String function cmd_model_delete(user_id : String, model_name : String):
	return "Not implemented: model_delete"!

String function cmd_model_list():
	// List all models
	log("Start model list @ " + cast_v2s(time()))
	Element models
	String result
	String m

	result = "Success: "
	models = allInstances(core, "Model")
	while (read_nr_out(models) > 0):
		m = set_pop(models)
		result = (result + string_join((string_join("  ", read_attribute(core, m, "name")) + " : "), read_attribute(core, set_pop(allAssociationDestinations(core, m, "instanceOf")), "name"))) + "\n"
	log("Finish model list @ " + cast_v2s(time()))
	return result!

String function cmd_model_list_full():
	// List all models with full info
	Element models
	String m
	String permissions
	String owner
	String group
	String name
	String type
	String result

	result = "Success: "
	models = allInstances(core, "Model")
	while (read_nr_out(models) > 0):
		m = set_pop(models)
		permissions = read_attribute(core, m, "permissions")
		owner = read_attribute(core, set_pop(allAssociationDestinations(core, m, "owner")), "name")
		group = read_attribute(core, set_pop(allAssociationDestinations(core, m, "group")), "name")
		name = read_attribute(core, m, "name")
		type = read_attribute(core, set_pop(allAssociationDestinations(core, m, "instanceOf")), "name")
		result = (result + ((((((((("  " + permissions) + " ") + owner) + " ") + group) + " ") + name) + " : ") + type)) + "\n"

	return result!

String function cmd_transformation_add_MT_language(user_id : String, model_names : Element, RAMified_name : String):
	// Create a model transformation language from a set of input and output formalisms
	String model_name
	String model_id
	Element source
	Element target
	Element all_formalisms
	Element merged_formalism
	Element ramified_formalism
	String type_id
	String location
	String new_model_id
	String type_name

	// Read involved formalisms
	all_formalisms = create_node()
	while (read_nr_out(model_names) > 0):
		model_name = set_pop(model_names)
		model_id = get_model_id(model_name)
		if (model_id != ""):
			if (allow_read(user_id, model_id)):
				type_name = read_attribute(core, set_pop(allAssociationDestinations(core, model_id, "instanceOf")), "name")
				type_id = get_model_id(type_name)
				if (type_name != "SimpleClassDiagrams"):
					return "Can only RAMify models of type SimpleClassDiagrams"!
				else:
					set_add(all_formalisms, create_tuple(model_name, get_full_model(model_id)))
			else:
				return "Permission denied to model: " + model_name!
		else:
			return "Model not found: " + model_name!

	// Merge all into a single metamodel
	if (read_nr_out(all_formalisms) > 0):
		if (get_model_id(RAMified_name) == ""):
			String merged_formalism_id
			String ramified_formalism_id
			String source_formalism_id
			String tracability_link

			// New location is available, so write
			merged_formalism = model_fuse(set_copy(all_formalisms))
			model_create(merged_formalism, "__merged_" + RAMified_name, user_id, type_id, "Model")
			merged_formalism_id = get_model_id("__merged_" + RAMified_name)

			// Add tracability links at this level
			while (read_nr_out(all_formalisms) > 0):
				source_formalism_id = get_model_id(list_read(set_pop(all_formalisms), 0))
				tracability_link = instantiate_link(core, "tracability", "", merged_formalism_id, source_formalism_id)
				instantiate_attribute(core, tracability_link, "type", "merged")

			// Merge complete, now RAMify!
			ramified_formalism = ramify(merged_formalism)
			model_create(ramified_formalism, RAMified_name, user_id, type_id, "Model")
			ramified_formalism_id = get_model_id(RAMified_name)

			// Add tracability link at this level
			tracability_link = instantiate_link(core, "tracability", "", ramified_formalism_id, merged_formalism_id)
			instantiate_attribute(core, tracability_link, "type", "RAMified")

			return "Success"!
		else:
			return "Model exists: " + RAMified_name!
	else:
		return "At least one formalism is required"!

String function cmd_transformation_RAMify(user_id : String, merged_model_name : String, target_model_name : String):
	// RAMify a metamodel
	String merged_model_id
	String target_model_id
	Element target_model
	String tracability_link

	merged_model_id = get_model_id(merged_model_name)
	if (merged_model_id != ""):
		if (allow_read(user_id, merged_model_id)):
			target_model_id = get_model_id(target_model_name)
			if (target_model_id == ""):
				// New model, so everything is fine
				target_model = ramify(get_full_model(merged_model_id))
				model_create(target_model, target_model_name, user_id, set_pop(allAssociationDestinations(core, merged_model_id, "instanceOf")), "Model")
				target_model_id = get_model_id(target_model_name)
				tracability_link = instantiate_link(core, "tracability", "", target_model_id, merged_model_id)
				instantiate_attribute(core, tracability_link, "type", "RAMified")
			else:
				// Existing model, so overwrite
				if (allow_write(user_id, target_model_id)):
					target_model = ramify(get_full_model(merged_model_id))
					model_overwrite(target_model, target_model_id)
					model_delete_element(core, set_pop(allOutgoingAssociationInstances(core, target_model_id, "tracability")))
					tracability_link = instantiate_link(core, "tracability", "", target_model_id, merged_model_id)
					instantiate_attribute(core, tracability_link, "type", "RAMified")
				else:
					return "Permission denied to model: " + target_model_name!
			return "Success"!
		else:
			return "Permission denied to model: " + merged_model_name!
	else:
		return "Model not found: " + merged_model_name!

String function cmd_transformation_add_MANUAL(user_id : String, source_model_names : Element, target_model_names : Element, operation_name : String):
	return transformation_add(user_id, source_model_names, target_model_names, operation_name, "manual")!

String function cmd_transformation_add_AL(user_id : String, source_model_names : Element, target_model_names : Element, operation_name : String):
	return transformation_add(user_id, source_model_names, target_model_names, operation_name, "actionlanguage")!

String function transformation_add(user_id : String, source_model_names : Element, target_model_names : Element, operation_name : String, operation_type : String):
	// Add a manual transformation model
	String model_id
	Element models
	Element source
	Element target
	String name
	Element all_formalisms
	Element merged_formalism
	String merged_formalism_id
	String source_formalism_id
	String tracability_link
	String type_id
	String old_type_id

	source = create_node()
	target = create_node()
	all_formalisms = create_node()

	type_id = ""
	old_type_id = ""

	while (read_nr_out(source_model_names) > 0):
		name = set_pop(source_model_names)
		model_id = get_model_id(name)
		if (model_id != ""):
			if (allow_read(user_id, model_id)):
				if (bool_not(set_in(source, model_id))):
					type_id = set_pop(allAssociationDestinations(core, model_id, "instanceOf"))
					if (bool_or(old_type_id == "", type_id == old_type_id)):
						old_type_id = type_id
						set_add(source, model_id)
						set_add(all_formalisms, create_tuple(name, get_full_model(model_id)))
					elif (old_type_id != type_id):
						// Already have a previous type_id and now another: CLASH
						return "Cannot add model as type not compatible with previous models: " + name!
				else:
					return "Model already selected as source: " + name!
			else:
				return "Permission denied to model: " + name!
		else:
			return "Model not found: " + name!

	while (read_nr_out(target_model_names) > 0):
		name = set_pop(target_model_names)
		model_id = get_model_id(name)
		if (model_id != ""):
			if (allow_read(user_id, model_id)):
				if (bool_not(set_in(target, model_id))):
					type_id = set_pop(allAssociationDestinations(core, model_id, "instanceOf"))
					if (bool_or(old_type_id == "", type_id == old_type_id)):
						old_type_id = type_id
						set_add(target, model_id)
						set_add(all_formalisms, create_tuple(name, get_full_model(model_id)))
					elif (old_type_id != type_id):
						// Already have a previous type_id and now another: CLASH
						return "Cannot add mdoel as type not compatible with previous models: " + name!
				else:
					return "Model already selected as target: " + name!
			else:
				return "Permission denied to model: " + name!
		else:
			return "Model not found: " + name!

	if (get_model_id(operation_name) == ""):
		if (operation_type == "manual"):
			// Finished with all information, now create the model itself!
			model_create(instantiate_model(get_full_model(get_model_id("ManualOperation"))), operation_name, user_id, get_model_id("ManualOperation"), "ManualOperation")
			model_id = get_model_id(operation_name)

		elif (operation_type == "actionlanguage"):
			// Finished with all information, now create the model itself!
			output("Waiting for code constructors...")
			add_code_model(get_full_model(get_model_id("ActionLanguage")), "AL/" + operation_name, construct_function())
			model_create(import_node("AL/" + operation_name), operation_name, user_id, get_model_id("ActionLanguage"), "ActionLanguage")
			model_id = get_model_id(operation_name)

		// Write out a merged metamodel containing all these models: this is the MM for the manual operation
		// New location is available, so write
		merged_formalism = model_fuse(set_copy(all_formalisms))
		model_create(merged_formalism, "__merged_" + operation_name, user_id, type_id, "Model")
		merged_formalism_id = get_model_id("__merged_" + operation_name)

		// Add tracability links at this level
		while (read_nr_out(all_formalisms) > 0):
			source_formalism_id = get_model_id(list_read(set_pop(all_formalisms), 0))
			tracability_link = instantiate_link(core, "tracability", "", merged_formalism_id, source_formalism_id)
			instantiate_attribute(core, tracability_link, "type", "merged")

		tracability_link = instantiate_link(core, "tracability", "", model_id, merged_formalism_id)
		instantiate_attribute(core, tracability_link, "type", "operatesOn")

		// Extend metadata with info on source and target
		String link
		String dst

		while (read_nr_out(source) > 0):
			dst = set_pop(source)
			link = instantiate_link(core, "transformInput", "", model_id, dst)

		while (read_nr_out(target) > 0):
			dst = set_pop(target)
			link = instantiate_link(core, "transformOutput", "", model_id, dst)
			
		return "Success"!
	else:
		return "Model exists: " + operation_name!

String function cmd_transformation_add_MT(user_id : String, RAMified_metamodel_name : String, source_models : Element, target_models : Element, operation_name : String):
	// Add a model transformation model
	// Just a usual model instantiation, but need to add the source and target links based on user info
	String ramified_metamodel_id
	String model_id
	Element models
	Element links
	String link_id
	Element supported
	Element source
	Element target
	String name
	String new_model_id
	String merged_link_id
	Element links_merged
	String merged_metamodel_id

	source = create_node()
	target = create_node()
	supported = create_node()
	ramified_metamodel_id = get_model_id(RAMified_metamodel_name)
	if (ramified_metamodel_id != ""):
		if (allow_read(user_id, ramified_metamodel_id)):
			links = allOutgoingAssociationInstances(core, ramified_metamodel_id, "tracability")
			while (read_nr_out(links) > 0):
				link_id = set_pop(links)
				merged_metamodel_id = readAssociationDestination(core, link_id)
				if (value_eq(read_attribute(core, link_id, "type"), "RAMified")):
					links_merged = allOutgoingAssociationInstances(core, merged_metamodel_id, "tracability")
					while (read_nr_out(links_merged) > 0):
						merged_link_id = set_pop(links_merged)
						if (value_eq(read_attribute(core, merged_link_id, "type"), "merged")):
							set_add(supported, readAssociationDestination(core, merged_link_id))

			while (read_nr_out(source_models) > 0):
				name = set_pop(source_models)
				model_id = get_model_id(name)
				if (model_id != ""):
					if (set_in(supported, model_id)):
						if (bool_not(set_in(source, model_id))):
							set_add(source, model_id)
						else:
							return "Model already selected: " + name!
					else:
						return "Model not supported by RAMified metamodel: " + name!
				else:
					return "Model not found: " + name!

			while (read_nr_out(target_models) > 0):
				name = set_pop(target_models)
				model_id = get_model_id(name)
				if (model_id != ""):
					if (set_in(supported, model_id)):
						if (bool_not(set_in(target, model_id))):
							set_add(target, model_id)
						else:
							return "Model already selected: " + name!
					else:
						return "Model not supported by RAMified metamodel: " + name!
				else:
					return "Model not found: " + name!
				
			if (get_model_id(operation_name) == ""):
				String new_model
				// Finished with all information, now create the model itself!
				output("Waiting for model constructors...")
				new_model = construct_model_raw(get_full_model(ramified_metamodel_id))
				model_create(new_model, operation_name, user_id, ramified_metamodel_id, "ModelTransformation")
				model_id = get_model_id(operation_name)

				// Extend metadata with info on source and target
				String link
				String dst

				while (read_nr_out(source) > 0):
					dst = set_pop(source)
					link = instantiate_link(core, "transformInput", "", model_id, dst)

				while (read_nr_out(target) > 0):
					dst = set_pop(target)
					link = instantiate_link(core, "transformOutput", "", model_id, dst)

				return "Success"!
			else:
				return "Model exists: " + operation_name!
		else:
			return "Permission denied to model: " + operation_name!
	else:
		return "Model not found: " + operation_name!

String function cmd_transformation_list():
	// List all models
	Element models
	String m
	String type
	String result

	result = ""
	models = allInstances(core, "Transformation")
	while (read_nr_out(models) > 0):
		m = set_pop(models)
		result = result + ((string_join(("[" + read_type(core, m)) + "]", string_join((string_join(" ", read_attribute(core, m, "name")) + " : "), read_attribute(core, set_pop(allAssociationDestinations(core, m, "instanceOf")), "name")))) + "\n")

	return result!

String function cmd_transformation_list_full():
	// List all models with full info
	Element models
	String m
	String permissions
	String owner
	String group
	String name
	String type
	String result

	result = ""
	models = allInstances(core, "Transformation")
	while (read_nr_out(models) > 0):
		m = set_pop(models)
		permissions = read_attribute(core, m, "permissions")
		owner = read_attribute(core, set_pop(allAssociationDestinations(core, m, "owner")), "name")
		group = read_attribute(core, set_pop(allAssociationDestinations(core, m, "group")), "name")
		name = read_attribute(core, m, "name")
		type = read_attribute(core, set_pop(allAssociationDestinations(core, m, "instanceOf")), "name")
		result = result + (((((((((("  " + permissions) + " ") + owner) + " ") + group) + " ") + ((("[" + read_type(core, m)) + "] ") + name)) + " : ") + type) + "\n")

	return result!

String function cmd_permission_modify(user_id : String, model_name : String, permissions : String):
	Integer permission
	String model_id

	model_id = get_model_id(model_name)
	if (model_id != ""):
		if (get_relation_to_model(user_id, model_id) == 0):
			Boolean fail
			Integer i
			i = 0
			if (string_len(permissions) != 3):
				fail = True

			while (i < 3):
				permission = cast_s2i(string_get(permissions, i))
				if (bool_or(permission < 0, permission > 2)):
					fail = True
					break!
				i = i + 1

			if (bool_not(fail)):
				unset_attribute(core, model_id, "permissions")
				instantiate_attribute(core, model_id, "permissions", permissions)
				return "Success"!
			else:
				return "Permission has incorrect format: must be a string of three characters, with each character being a digit between 0 and 2"!
		else:
			return "Permission denied to model: " + model_name!
	else:
		return "Model not found: " + model_name!

String function cmd_permission_owner(user_id : String, model_name : String, new_user_name : String):
	String model_id
	String new_user_id

	model_id = get_model_id(model_name)
	if (model_id != ""):
		if (bool_or(get_relation_to_model(user_id, model_id) == 0, is_admin(user_id))):
			new_user_id = get_user_id(new_user_name)
			if (new_user_id != ""):
				model_delete_element(core, set_pop(allOutgoingAssociationInstances(core, model_id, "owner")))
				instantiate_link(core, "owner", "", model_id, new_user_id)
				return "Success"!
			else:
				return "No such user: " + new_user_name!
		else:
			return "Permission denied to model: " + model_name!
	else:
		return "Model not found: " + model_name!

String function cmd_permission_group(user_id : String, model_name : String, new_group_name : String):
	String model_id
	String group_id

	model_id = get_model_id(model_name)
	if (model_id != ""):
		if (bool_or(get_relation_to_model(user_id, model_id) == 0, is_admin(user_id))):
			group_id = get_group_id(new_group_name)
			if (group_id != ""):
				model_delete_element(core, set_pop(allOutgoingAssociationInstances(core, model_id, "group")))
				instantiate_link(core, "group", "", model_id, group_id)
				return "Success"!
			else:
				return "No such group: " + new_group_name!
		else:
			return "Permission denied to model: " + model_name!
	else:
		return "Model not found: " + model_name!

String function cmd_group_create(user_id : String, group_name : String):
	// Create a new group and become its owner
	String group_id
	String name

	group_id = get_group_id(group_name)
	if (group_id == ""):
		group_id = instantiate_node(core, "Group", "")
		instantiate_attribute(core, group_id, "name", group_name)
		instantiate_link(core, "belongsTo", "", user_id, group_id)
		instantiate_link(core, "owner", "", group_id, user_id)
		return "Success"!
	else:
		return "Group exists: " + group_name!

String function cmd_group_delete(user_id : String, group_name : String):
	// Delete an existing group
	String group_id

	group_id = get_group_id(group_name)
	if (group_id != ""):
		if (allow_group_modify(user_id, group_id)):
			model_delete_element(core, group_id)
			return "Success"!
		else:
			return "Permission denied to group: " + group_name!
	else:
		return "Group not found: " + group_name!

String function cmd_group_owner_add(user_id : String, group_name : String, other_user_name : String):
	// Add an owner to your group
	String group_id
	String other_user_id

	group_id = get_group_id(group_name)
	if (group_id != ""):
		if (allow_group_modify(user_id, group_id)):
			other_user_id = get_user_id(other_user_name)
			if (other_user_id != ""):
				Element overlap

				overlap = set_overlap(allIncomingAssociationInstances(core, other_user_id, "owner"), allOutgoingAssociationInstances(core, group_id, "owner"))
				if (read_nr_out(overlap) == 0):
					instantiate_link(core, "owner", "", group_id, other_user_id)

					overlap = set_overlap(allOutgoingAssociationInstances(core, other_user_id, "belongsTo"), allIncomingAssociationInstances(core, group_id, "belongsTo"))

					if (read_nr_out(overlap) == 0):
						instantiate_link(core, "belongsTo", "", other_user_id, group_id)

					return "Success"!
				else:
					return "User is already the owner!"!
			else:
				return "User not found: " + other_user_name!
		else:
			return "Permission denied to group: " + group_name!
	else:
		return "Group not found: " + group_name!

String function cmd_group_owner_delete(user_id : String, group_name : String, other_user_name : String):
	// Remove an owner from your group
	String group_id
	String other_user_id

	group_id = get_group_id(group_name)
	if (group_id != ""):
		if (allow_group_modify(user_id, group_id)):
			other_user_id = get_user_id(other_user_name)
			if (other_user_id != ""):
				Element overlap

				overlap = set_overlap(allOutgoingAssociationInstances(core, other_user_id, "belongsTo"), allIncomingAssociationInstances(core, group_id, "belongsTo"))
				if (read_nr_out(overlap) > 0):
					overlap = set_overlap(allIncomingAssociationInstances(core, other_user_id, "owner"), allOutgoingAssociationInstances(core, group_id, "owner"))
					if (read_nr_out(overlap) > 0):
						model_delete_element(core, set_pop(overlap))
						return "Success"!
					else:
						return "User is not an owner of the group!"!
				else:
					return "User is not a member of the group!"!
			else:
				return "User not found: " + other_user_name!
		else:
			return "Permission denied to group: " + group_name!
	else:
		return "Group not found: " + group_name!

String function cmd_group_join(user_id : String, group_name : String, other_user_name : String):
	// Add someone to your group
	String group_id
	String other_user_id

	group_id = get_group_id(group_name)
	if (group_id != ""):
		if (allow_group_modify(user_id, group_id)):
			other_user_id = get_user_id(other_user_name)
			if (other_user_id != ""):
				Element overlap
				overlap = set_overlap(allOutgoingAssociationInstances(core, other_user_id, "belongsTo"), allIncomingAssociationInstances(core, group_id, "belongsTo"))

				if (read_nr_out(overlap) == 0):
					instantiate_link(core, "belongsTo", "", other_user_id, group_id)
					return "Success"!
				else:
					return "User is already a member of the group!"!
			else:
				return "User not found: " + other_user_name!
		else:
			return "Permission denied to group: " + group_name!
	else:
		return "Group not found: " + group_name!

String function cmd_group_kick(user_id : String, group_name : String, other_user_name : String):
	// Remove someone from your group
	String group_id
	String other_user_id

	group_id = get_group_id(group_name)
	if (group_id != ""):
		if (allow_group_modify(user_id, group_id)):
			other_user_id = get_user_id(other_user_name)
			if (other_user_id != ""):
				Element overlap
				overlap = set_overlap(allOutgoingAssociationInstances(core, other_user_id, "belongsTo"), allIncomingAssociationInstances(core, group_id, "belongsTo"))

				if (read_nr_out(overlap) > 0):
					model_delete_element(core, set_pop(overlap))

					// Check if user was an owner as well
					overlap = set_overlap(allIncomingAssociationInstances(core, other_user_id, "owner"), allOutgoingAssociationInstances(core, group_id, "owner"))
					if (read_nr_out(overlap) > 0):
						model_delete_element(core, set_pop(overlap))

					return "Success"!
				else:
					return "User is not a member of the group!"!
			else:
				return "User not found: " + other_user_name!
		else:
			return "Permission denied to group: " + group_name!
	else:
		return "Group not found: " + group_name!

String function cmd_group_list(user_id : String):
	// List all groups you are a member of (and whether you are admin or not!)
	Element groups
	String group_id
	String admin
	String result
	
	result = ""
	groups = allAssociationDestinations(core, user_id, "belongsTo")
	while (read_nr_out(groups) > 0):
		group_id = set_pop(groups)
		if (set_in(allOutgoingAssociationInstances(core, group_id, "owner"), user_id)):
			admin = " A "
		else:
			admin = "   "

		result = result + (string_join(admin, read_attribute(core, group_id, "name")) + "\n")

	return result!

String function cmd_admin_promote(user_id : String, other_user_name : String):
	// Promote a user to admin status
	if (is_admin(user_id)):
		String other_user_id

		other_user_id = get_user_id(other_user_name)
		if (other_user_id != ""):
			unset_attribute(core, other_user_id, "admin")
			instantiate_attribute(core, other_user_id, "admin", True)
			return "Success"!
		else:
			return "User not found: " + other_user_name!
	else:
		return "Permission denied to administrate: " + other_user_name!

String function cmd_admin_demote(user_id : String, other_user_name : String):
	// Demote a user to normal status
	if (is_admin(user_id)):
		String other_user_id

		other_user_id = get_user_id(other_user_name)
		if (other_user_id != ""):
			unset_attribute(core, other_user_id, "admin")
			instantiate_attribute(core, other_user_id, "admin", False)
			return "Success"!
		else:
			return "User not found: " + other_user_name!
	else:
		return "Permission denied to administrate: " + other_user_name!

Void function user_function_skip_init(user_id : String):
	String cmd

	output("Welcome to the Model Management Interface v2.0!")
	output("Use the 'help' command for a list of possible commands")

	while (True):
		cmd = input()
		if (cmd == "help"):
			output(cmd_help(user_id))
		elif (cmd == "model_add"):
			output(cmd_model_add(user_id, single_input("Model type?"), single_input("Model name?")))
		elif (cmd == "process_execute"):
			output(cmd_process_execute(user_id, single_input("Process to execute?"), single_input("Model prefix to use?")))
		elif (cmd == "transformation_between"):
			output(cmd_transformation_between(user_id, single_input("Source type?"), single_input("Target type?")))
		elif (cmd == "model_render"):
			output(cmd_model_render(user_id, single_input("Model name?"), single_input("Mapper name?")))
		elif (cmd == "transformation_execute"):
			output(cmd_transformation_execute(user_id, single_input("Transformation name?"), dict_input("Source models?"), dict_input("Target models?")))
		elif (cmd == "verify"):
			output(cmd_verify(user_id, single_input("Model name?")))
		elif (cmd == "model_overwrite"):
			output(cmd_model_overwrite(user_id, single_input("Model name?")))
		elif (cmd == "model_modify"):
			output(cmd_model_modify(user_id, single_input("Model name?")))
		elif (cmd == "model_delete"):
			output(cmd_model_delete(user_id, single_input("Model name?")))
		elif (cmd == "model_list"):
			output(cmd_model_list())
		elif (cmd == "model_list_full"):
			output(cmd_model_list_full())
		elif (cmd == "transformation_add_MT_language"):
			output(cmd_transformation_add_MT_language(user_id, set_input("Metamodel names?"), single_input("RAMified metamodel name?")))
		elif (cmd == "transformation_RAMify"):
			output(cmd_transformation_RAMify(user_id, single_input("Metamodel name?"), single_input("Target metamodel name?")))
		elif (cmd == "transformation_add_MANUAL"):
			output(cmd_transformation_add_MANUAL(user_id, set_input("Source model names?"), set_input("Target model names?"), single_input("Operation name?")))
		elif (cmd == "transformation_add_AL"):
			output(cmd_transformation_add_AL(user_id, set_input("Source model names?"), set_input("Target model names?"), single_input("Operation name?")))
		elif (cmd == "transformation_add_MT"):
			output(cmd_transformation_add_MT(user_id, single_input("RAMified metamodel name?"), set_input("Source model names?"), set_input("Target models?"), single_input("Operation name?")))
		elif (cmd == "transformation_list"):
			output(cmd_transformation_list())
		elif (cmd == "transformation_list_full"):
			output(cmd_transformation_list_full())
		elif (cmd == "permission_modify"):
			output(cmd_permission_modify(user_id, single_input("Model name?"), single_input("Permissions?")))
		elif (cmd == "permission_owner"):
			output(cmd_permission_owner(user_id, single_input("Model name?"), single_input("New owning user?")))
		elif (cmd == "permission_group"):
			output(cmd_permission_group(user_id, single_input("Model name?"), single_input("New owning group?")))
		elif (cmd == "group_create"):
			output(cmd_group_create(user_id, single_input("New group name?")))
		elif (cmd == "group_delete"):
			output(cmd_group_delete(user_id, single_input("Group name?")))
		elif (cmd == "group_owner_add"):
			output(cmd_group_owner_add(user_id, single_input("Group name?"), single_input("User name?")))
		elif (cmd == "group_owner_delete"):
			output(cmd_group_owner_delete(user_id, single_input("Group name?"), single_input("User name?")))
		elif (cmd == "group_join"):
			output(cmd_group_join(user_id, single_input("Group name?"), single_input("User name?")))
		elif (cmd == "group_kick"):
			output(cmd_group_kick(user_id, single_input("Group name?"), single_input("User name?")))
		elif (cmd == "group_list"):
			output(cmd_group_list(user_id))
		elif (cmd == "admin_promote"):
			output(cmd_admin_promote(user_id, single_input("User name?")))
		elif (cmd == "admin_demote"):
			output(cmd_admin_demote(user_id, single_input("User name?")))
		elif (cmd == "verbose"):
			set_verbose(True)
		elif (cmd == "quiet"):
			set_verbose(False)
		elif (cmd == "self-destruct"):
			// Delete user from Core Formalism
			model_delete_element(core, user_id)
			return !
		elif (cmd == "exit"):
			// Exit by actually removing the user and decoupling it from all of its models
			// Restarting with the same user name will NOT grant you access to anything of the previous user with that same name
			// as the current user will have been deleted
			return !
		else:
			output("Unknown command: " + cmd)

	// We never get here!
	return !