modelverse/bootstrap/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"
include "utils.alh"

Element core = ?

String core_model_location = "models/core"

Void function initialize_core():
	// TODO make this more flexible by putting it in the bootstrap in a similar way as other models
	add_code_model(import_node("models/ActionLanguage"), "models/Conformance_MV", wrap_conformance)

	return !

Element function get_instanceOf_links(model_id : String, metamodel_id : String):
	return set_overlap(allOutgoingAssociationInstances(core, model_id, "instanceOf"), allIncomingAssociationInstances(core, metamodel_id, "instanceOf"))!

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

	all_links = set_overlap(allOutgoingAssociationInstances(core, model_id, "instanceOf"), allIncomingAssociationInstances(core, metamodel_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; crashing")
	
	choice = set_pop(all_links)

	return choice!

Element function get_full_model(model_id : String, metamodel_id : String):
	// TODO we are restricted to using SimpleClassDiagrams as M3 level, through this code!
	Element m
	Element all_links
	String choice

	choice = get_instanceOf_link(model_id, metamodel_id)

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

	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), get_model_id("SimpleClassDiagrams")))
		
	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!

Void function new_task():
	String username
	String user_id
	String password

	// 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
	return!

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_service_id(name : String):
	Element services
	String service

	services = allInstances(core, "Service")

	log("Search " + name)
	while (read_nr_out(services) > 0):
		service = set_pop(services)
		log("Check " + cast_v2s(read_attribute(core, service, "name")))
		if (value_eq(read_attribute(core, service, "name"), name)):
			log("Match!")
			return service!
	
	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)

	location = "models/" + cast_id2s(model["type_mapping"])
	export_node(location, model["type_mapping"])
	instantiate_attribute(core, instance_of, "typing_location", location)
	instantiate_link(core, "semantics", "", instance_of, get_model_id("conformance_mv"))

	return!

Void function model_overwrite(model : Element, model_id : String, metamodel_id : String):
	// TODO this should be more elegant than just hiding the old elements

	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)

	// Update the instanceOf relation of the context in which we are working
	// TODO This needs to be fixed: all previous connections should be cleared probably
	instanceOf_link = get_instanceOf_link(model_id, metamodel_id)
	unset_attribute(core, instanceOf_link, "typing_location")
	location = "models/" + cast_id2s(model["type_mapping"])
	export_node(location, model["type_mapping"])
	instantiate_attribute(core, instanceOf_link, "typing_location", location)

	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_models : 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 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

	// 0) Find the signature of the operation
	Element input_metamodels
	Element output_metamodels
	Element iter
	String edge
	input_metamodels = create_node()
	iter = allOutgoingAssociationInstances(core, operation_id, "transformInput")
	while (read_nr_out(iter) > 0):
		edge = set_pop(iter)
		dict_add(input_metamodels, read_attribute(core, edge, "name"), read_attribute(core, readAssociationDestination(core, edge), "name"))

	output_metamodels = create_node()
	iter = allOutgoingAssociationInstances(core, operation_id, "transformOutput")
	while (read_nr_out(iter) > 0):
		edge = set_pop(iter)
		dict_add(output_metamodels, read_attribute(core, edge, "name"), read_attribute(core, readAssociationDestination(core, edge), "name"))

	// 1) Find merged metamodel

	exact_type = read_type(core, operation_id)
	trace_links = allOutgoingAssociationInstances(core, operation_id, "tracability")
	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"), "operatesOn")):
			merged_metamodel_id = readAssociationDestination(core, trace_link_id)

	// 2) Merge source models

	if (merged_metamodel_id != ""):
		model_tuples = create_node()
		keys = dict_keys(input_models)
		while (read_nr_out(keys) > 0):
			key = set_pop(keys)
			set_add(model_tuples, create_tuple(key, get_full_model(get_model_id(input_models[key]), get_model_id(input_metamodels[key]))))

		merged_model = model_join(model_tuples, get_full_model(merged_metamodel_id, get_model_id("SimpleClassDiagrams")), tracability_model)
	else:
		if (bool_and(read_nr_out(input_models) == 1, read_nr_out(output_models) == 0)):
			// Just skip the merge...
			merged_model = model_copy(get_full_model(get_model_id(set_read(input_models)), get_model_id(set_read(input_metamodels))))
		elif (bool_and(read_nr_out(input_models) == 0, read_nr_out(output_models) == 0)):
			merged_model = read_root()
		else:
			log("Could not resolve intermediate merged metamodel")
			output("Could not resolve intermediate merged metamodel")
			return read_root()!

	// 3) Transform

	if (exact_type == "ModelTransformation"):
		result = transform(merged_model, get_full_model(operation_id, merged_metamodel_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, get_model_id("ActionLanguage")))
		result = func(merged_model)
	else:
		log("Unknown type of operation: " + exact_type)
		output("Unknown type of operation: " + exact_type)
		return read_root()!

	// 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()
		keys = dict_keys(output_models)
		while (read_nr_out(keys) > 0):
			key = set_pop(keys)
			set_add(model_tuples, create_tuple(key, get_full_model(get_model_id(output_models[key]), get_model_id(output_metamodels[key]))))

		result = model_split(merged_model, model_tuples, tracability)

		//log("Output models:")
		//keys = dict_keys(result)
		//while (read_nr_out(keys) > 0):
		//	key = set_pop(keys)
		//	log((cast_v2s(key) + " --> ") + cast_v2s(read_nr_out(result[key]["model"])))

		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:
		log("Negative result of execution")
		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
	String consume
	String produce
	Element output_map

	inputs = create_node()
	outputs = create_node()
	output_map = 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):
		consume = set_pop(lst)
		value = read_attribute(pm, readAssociationDestination(pm, consume), "name")
		dict_add(inputs, read_attribute(pm, consume, "name"), prefix + value)

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

	if read_type(core, transformation_id) == "ActionLanguage":
		log(string_join("Enacting ActionLanguage: ", read_attribute(pm, element, "name")))
		output(string_join("Enacting ActionLanguage: ", read_attribute(pm, element, "name")))
	elif read_type(core, transformation_id) == "ManualOperation":
		log(string_join("Enacting ManualOperation: ", read_attribute(pm, element, "name")))
		output(string_join("Enacting ManualOperation: ", read_attribute(pm, element, "name")))
	else:
		log(string_join("Enacting ModelTransformation: ", read_attribute(pm, element, "name")))
		output(string_join("Enacting ModelTransformation: ", read_attribute(pm, element, "name")))
		
	result = execute_operation(transformation_id, inputs, 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(output_map[key]) == ""):
				// New model
				model_create(result[key], output_map[key], user_id, get_model_id(key), "Model")
			else:
				model_overwrite(result[key], get_model_id(output_map[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

	output("Success")

	// 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]

		// 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
	output("Success")
	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           -- 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_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, get_model_id("SimpleClassDiagrams")))
				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, get_model_id("ProcessModel")), 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
	Element inputs
	Element output_map
	Element rendered_model
	Element tracability_model
	Element result
	Element out_links
	String link

	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()
					dict_add(inputs, "abstract", model_name)
					dict_add(inputs, "rendered", rendered_name)

					// Fetch the output types
					output_map = create_node()
					out_links = allOutgoingAssociationInstances(core, mapper_ID, "transformOutput")
					while(read_nr_out(out_links) > 0):
						link = set_pop(out_links)
						dict_add(output_map, read_attribute(core, link, "name"), read_attribute(core, readAssociationDestination(core, link), "name"))

					if (get_model_id(rendered_name) == ""):
						// Instantiate
						rendered_model = instantiate_model(get_full_model(get_model_id(output_map["rendered"]), get_model_id("SimpleClassDiagrams")))
						model_create(rendered_model, rendered_name, user_id, get_model_id(output_map["rendered"]), "Model")
						
						// Tracability model won't exist either
						tracability_model = instantiate_model(get_full_model(get_model_id("Tracability"), get_model_id("SimpleClassDiagrams")))
						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), get_model_id("TracabilityModel"))

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

					// Overwrite the previous rendered model
					model_overwrite(result["rendered"], get_model_id(rendered_name), get_model_id(output_map["rendered"]))
					model_overwrite(result["abstract"], get_model_id(model_name), get_model_id(output_map["abstract"]))

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

					// Also output the resulting model
					return "Success: " + JSON_print(get_full_model(get_model_id(rendered_name), get_model_id(output_map["rendered"])))!
				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 output_map
	Element trace_links
	String target_model_name
	String source_model_name
	String source_model_ID
	Element result
	Element keys
	String key
	String assoc_name

	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)
					assoc_name = read_attribute(core, source, "name")
					if (dict_in(source_models, assoc_name)):
						source_model_name = source_models[assoc_name]
					else:
						return "Source model not bound: " + assoc_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)):
									dict_add(inputs, assoc_name, 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()
				output_map = create_node()
				while (read_nr_out(targets) > 0):
					target = set_pop(targets)
					assoc_name = read_attribute(core, target, "name")
					if (dict_in(target_models, assoc_name)):
						target_model_name = target_models[assoc_name]
					else:
						return "Target model not bound: " + assoc_name!

					if (get_model_id(target_model_name) == ""):
						// Doesn't exist yet, so we can easily create
						dict_add(output_map, assoc_name, read_attribute(core, readAssociationDestination(core, target), "name"))
						dict_add(outputs, assoc_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(output_map, assoc_name, read_attribute(core, readAssociationDestination(core, target), "name"))
							dict_add(outputs, assoc_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")

				log("Start execution: " + cast_e2s(transformation_id))
				result = execute_operation(transformation_id, inputs, output_map, 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]), get_model_id(output_map[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, metamodel_name : String):
	// Check whether a model conforms to its specification (with the selected type mapping)
	String model_id
	String result
	Element inputs

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

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

	model_id = get_model_id(model_name)
	if (model_id != ""):
		if (allow_read(user_id, model_id)):
			String conformance_operation
			Element conformance

			conformance_operation = set_pop(allAssociationDestinations(core, get_instanceOf_link(model_id, get_model_id(metamodel_name)), "semantics"))
			inputs = create_node()
			dict_add(inputs, "SimpleClassDiagrams", model_name)
			result = execute_operation(conformance_operation, inputs, create_node(), read_root())
			return ""!
		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, metamodel_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(get_model_id(metamodel_name), get_model_id("SimpleClassDiagrams")))
				model_overwrite(new_model, model_id, metamodel_name)
				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, metamodel_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, get_model_id(metamodel_name)), 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):
	String model_id
	model_id = get_model_id(model_name)

	if (model_id != ""):
		if (allow_write(user_id, model_id)):
			model_delete_element(core, model_id)
			return "Success"!
		else:
			return "Permission denied to model: " + model_name!
	else:
		return "Model not found: " + model_name!

String function cmd_model_list():
	// List all models
	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"
	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_MANUAL(user_id : String, source_models : Element, target_models : Element, operation_name : String):
	return transformation_add(user_id, source_models, target_models, operation_name, "manual")!

String function cmd_transformation_add_AL(user_id : String, source_models : Element, target_models : Element, operation_name : String):
	return transformation_add(user_id, source_models, target_models, operation_name, "actionlanguage")!

String function transformation_add(user_id : String, source_models : Element, target_models : 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 formalism_map
	Element merged_formalism
	String merged_formalism_id
	String source_formalism_id
	String tracability_link
	Element keys
	String key

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

	keys = dict_keys(source_models)
	while (read_nr_out(keys) > 0):
		key = set_pop(keys)
		name = source_models[key]
		model_id = get_model_id(name)
		if (model_id != ""):
			if (allow_read(user_id, model_id)):
				if (bool_not(dict_in(source, key))):
					dict_add(source, key, model_id)
					set_add(formalism_map, create_tuple(key, get_full_model(model_id, get_model_id("SimpleClassDiagrams"))))
					if (bool_not(set_in(all_formalisms, model_id))):
						set_add(all_formalisms, model_id)
				else:
					return "Name already selected for source: " + key!
			else:
				return "Permission denied to model: " + name!
		else:
			return "Model not found: " + name!

	keys = dict_keys(target_models)
	while (read_nr_out(keys) > 0):
		key = set_pop(keys)
		name = target_models[key]
		model_id = get_model_id(name)
		if (model_id != ""):
			if (allow_read(user_id, model_id)):
				if (bool_not(dict_in(target, key))):
					dict_add(target, key, model_id)
					set_add(formalism_map, create_tuple(key, get_full_model(model_id, get_model_id("SimpleClassDiagrams"))))
					if (bool_not(set_in(all_formalisms, model_id))):
						set_add(all_formalisms, model_id)
				else:
					return "Name already selected for target: " + key!
			else:
				return "Permission denied to model: " + name!
		else:
			return "Model not found: " + name!

	if (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
		if (bool_not(bool_and(read_nr_out(source_models) == 0, read_nr_out(target_models) == 0))):
			merged_formalism = model_fuse(set_copy(formalism_map))
			modify(merged_formalism, True)

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

		if (bool_not(bool_and(read_nr_out(source_models) == 0, read_nr_out(target_models) == 0))):
			model_create(merged_formalism, "__merged_" + operation_name, user_id, get_model_id("SimpleClassDiagrams"), "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 = set_pop(all_formalisms)
				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

			keys = dict_keys(source)
			while (read_nr_out(keys) > 0):
				key = set_pop(keys)
				link = instantiate_link(core, "transformInput", "", model_id, source[key])
				instantiate_attribute(core, link, "name", key)

			keys = dict_keys(target)
			while (read_nr_out(keys) > 0):
				key = set_pop(keys)
				link = instantiate_link(core, "transformOutput", "", model_id, target[key])
				instantiate_attribute(core, link, "name", key)
				
		return "Success"!
	else:
		return "Model exists: " + operation_name!

String function cmd_transformation_add_MT(user_id : 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
	Element ramified_metamodel
	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_formalism
	Element keys
	String key
	String mm
	Element to_ramify
	String source_formalism_id
	String merged_formalism_id
	String tracability_link

	source = create_node()
	target = create_node()
	to_ramify = create_node()

	keys = dict_keys(source_models)
	while (read_nr_out(keys) > 0):
		key = set_pop(keys)
		name = source_models[key]
		model_id = get_model_id(name)
		if (model_id != ""):
			if (allow_read(user_id, name)):
				// Check whether or not it is SimpleClassDiagrams
				if (read_nr_out(get_instanceOf_links(model_id, get_model_id("SimpleClassDiagrams"))) > 0):
					if (bool_not(dict_in(source, key))):
						dict_add(source, key, model_id)
						set_add(to_ramify, create_tuple(key, get_full_model(model_id, get_model_id("SimpleClassDiagrams"))))
					else:
						return "Name was already assigned a metamodel: " + key!
				else:
					return "Model not supported for RAMification: " + name!
			else:
				return "Permission denied: " + name!
		else:
			return "Model not found: " + name!

	keys = dict_keys(target_models)
	while (read_nr_out(keys) > 0):
		key = set_pop(keys)
		name = target_models[key]
		model_id = get_model_id(name)
		if (model_id != ""):
			if (allow_read(user_id, name)):
				if (read_nr_out(get_instanceOf_links(model_id, get_model_id("SimpleClassDiagrams"))) > 0):
					if (bool_not(dict_in(target, key))):
						if (dict_in(source, key)):
							if (value_eq(model_id, source[key])):
								dict_add(target, key, model_id)
								// Don't add to to_ramify, as it is already in there!
							else:
								return "Name in output cannot have different type than input: " + key!
						else:
							dict_add(target, key, model_id)
							set_add(to_ramify, create_tuple(key, get_full_model(model_id, get_model_id("SimpleClassDiagrams"))))
					else:
						return "Name was already assigned a metamodel: " + key!
				else:
					return "Model not supported for RAMification: " + name!
			else:
				return "Permission denied: " + name!
		else:
			return "Model not found: " + name!

	merged_formalism = model_fuse(to_ramify)
	modify(merged_formalism, True)

	ramified_metamodel = ramify(merged_formalism)
	model_create(ramified_metamodel, "__RAM_" + operation_name, user_id, get_model_id("SimpleClassDiagrams"), "Model")
	ramified_metamodel_id = get_model_id("__RAM_" + operation_name)
	
	// Now use the RAMified model to create the instance
	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, get_model_id("SimpleClassDiagrams")))
		model_create(new_model, operation_name, user_id, ramified_metamodel_id, "ModelTransformation")
		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
		model_create(merged_formalism, "__merged_" + operation_name, user_id, get_model_id("SimpleClassDiagrams"), "Model")
		merged_formalism_id = get_model_id("__merged_" + operation_name)

		// Add tracability links at this level
		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

		keys = dict_keys(source)
		while (read_nr_out(keys) > 0):
			key = set_pop(keys)
			dst = source[key]
			link = instantiate_link(core, "transformInput", "", model_id, dst)
			instantiate_attribute(core, link, "name", key)

		keys = dict_keys(target)
		while (read_nr_out(keys) > 0):
			key = set_pop(keys)
			dst = target[key]
			link = instantiate_link(core, "transformOutput", "", model_id, dst)
			instantiate_attribute(core, link, "name", key)

		return "Success"!
	else:
		return "Model exists: " + operation_name!

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

	result = "Success: "
	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!

String function cmd_service_register(user_id : String, service_name : String):
	// Active a service for this specific user
	if (get_service_id(service_name) == ""):
		String service
		service = instantiate_node(core, "Service", "")
		instantiate_attribute(core, service, "name", service_name)
		instantiate_attribute(core, service, "port", get_taskname())
		output("Success: " + get_taskname())

		// Wait until we can stop the service
		log("Waiting for service_stop")
		while (cast_v2s(input()) != "\"service_stop\""):
			output("Service is running on this task: stop it by sending 'service_stop'")
		log("Finished")

		model_delete_element(core, service)

		// Service terminated
		return "Success"!
	else:
		return "Service already exists: " + service_name!

String function cmd_user_password(user_id : String, user_name : String, new_password : String):
	if (bool_or(user_id == get_user_id(user_name), is_admin(user_id))):
		if (get_user_id(user_name) != ""):
			instantiate_attribute(core, get_user_id(user_name), "password", hash(new_password))
			return "Success"!
		else:
			return "No such user: " + user_name!
	else:
		return "Permission denied to user: " + user_name!

String function cmd_transformation_signature(user_id : String, transformation_name : String):
	String model_id
	model_id = get_model_id(transformation_name)

	if (model_id != ""):
		if (is_nominal_instance(core, model_id, "Transformation")):
			if (allow_read(user_id, transformation_name)):
				String result
				String elem
				Element inputs
				Element outputs

				result = "Success: "
				inputs = allOutgoingAssociationInstances(core, model_id, "transformInput")
				while (read_nr_out(inputs) > 0):
					elem = set_pop(inputs)
					result = string_join(string_join(string_join(string_join("I ", read_attribute(core, elem, "name")), " "), read_attribute(core, readAssociationDestination(core, elem), "name")), "\n")

				outputs = allOutgoingAssociationInstances(core, model_id, "transformOutput")
				while (read_nr_out(outputs) > 0):
					elem = set_pop(outputs)
					result = string_join(string_join(string_join(string_join("O ", read_attribute(core, elem, "name")), " "), read_attribute(core, readAssociationDestination(core, elem), "name")), "\n")

				return result!
			else:
				return "Permission denied to transformation: " + transformation_name!
		else:
			return "Model is not a transformation: " + transformation_name!
	else:
		return "No such transformation: " + transformation_name!
	
String function cmd_element_list_nice(user_id : String, model_name : String, metamodel_name : String):
	if (get_model_id(model_name) != ""):
		if (allow_read(user_id, get_model_id(model_name))):
			return "Success: " + JSON_print(get_full_model(get_model_id(model_name), get_model_id(metamodel_name)))!
		else:
			return "Permission denied to model: " + model_name!
	else:
		return "No such model: " + model_name!

Void function user_function_skip_init(user_id : String):
	String cmd
	String result

	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"):
			result = cmd_verify(user_id, single_input("Model name?"), single_input("Metamodel name?"))
			if (result != ""):
				output(result)
		elif (cmd == "model_overwrite"):
			output(cmd_model_overwrite(user_id, single_input("Model name?"), single_input("Metamodel name?")))
		elif (cmd == "model_modify"):
			output(cmd_model_modify(user_id, single_input("Model name?"), single_input("Metamodel 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_MANUAL"):
			output(cmd_transformation_add_MANUAL(user_id, dict_input("Source model names?"), dict_input("Target model names?"), single_input("Operation name?")))
		elif (cmd == "transformation_add_AL"):
			output(cmd_transformation_add_AL(user_id, dict_input("Source model names?"), dict_input("Target model names?"), single_input("Operation name?")))
		elif (cmd == "transformation_add_MT"):
			output(cmd_transformation_add_MT(user_id, dict_input("Source model names?"), dict_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 == "service_register"):
			output(cmd_service_register(user_id, single_input("Service name?")))
		elif (cmd == "user_password"):
			output(cmd_user_password(user_id, single_input("User name?"), single_input("New password?")))
		elif (cmd == "transformation_read_signature"):
			output(cmd_transformation_signature(user_id, single_input("Transformation name?")))
		elif (cmd == "element_list_nice"):
			output(cmd_element_list_nice(user_id, single_input("Model name?"), single_input("Metamodel 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 !