abstract xor EventOptions
	PresentInWhole
	PresentInRemainder
	PresentInNextComboStep
	PresentInNextSmallStep
	PresentInSame
		[BSML.Semantics.ConcurrencyAndConsistency.Concurrency.Many]

abstract BSML
	Syntax
		Events?
			[Semantics.EventLifeLine]
			EventTriggers?
				EnvironmentalInputEvents?
					[Semantics.EventLifeLine.ExternalEvents.ExternalInputEvents.ExternalInputEventOptions.SyntacticInputEvents]
					NegatedEnvironmentalnputEvents?
						[Semantics.Priority.NegationOfTriggers]
				InterfaceEvents?
					[Syntax.Events.GeneratedEvents.GeneratedInterfaceEvents]
					[Semantics.EventLifeLine.InterfaceEvents]
					NegatedInterfaceEvents?
						[Semantics.Priority.NegationOfTriggers]
				NegatedEvents?
					[Semantics.Priority.NegationOfTriggers]
			GeneratedEvents?
				EnvironmentalOutputEvents?
					[Semantics.EventLifeLine.ExternalEvents.ExternalOutputEvents.ExternalOutputEventOptions.SyntacticOutputEvents]
				GeneratedInterfaceEvents?
					[Syntax.Events.EventTriggers.InterfaceEvents]

		Variables?
			VariableOperators // in Day & Atlee, this is an optional feature, but it may not have to be optional because all its nested clafers are optional too.
				new?
					[Semantics.OrderOfSmallSteps.Dataflow]
					[Semantics.EnablednessMemoryProtocol.InternalVariablesInGC.GCBigStep ||
					 Semantics.EnablednessMemoryProtocol.InternalVariablesInGC.GCSmallStep ||
					 Semantics.AssignmentMemoryProtocol.InternalVariablesInRHS.RHSBigStep ||
					 Semantics.AssignmentMemoryProtocol.InternalVariablesInRHS.RHSSmallStep]
				new_small?
					[Semantics.EnablednessMemoryProtocol.InternalVariablesInGC.GCSmallStep ||
					 Semantics.AssignmentMemoryProtocol.InternalVariablesInRHS.RHSSmallStep]
				cur?
					[Semantics.EnablednessMemoryProtocol.InternalVariablesInGC.GCBigStep ||
					 Semantics.AssignmentMemoryProtocol.InternalVariablesInRHS.RHSBigStep]
				pre?
					[Semantics.EnablednessMemoryProtocol.InternalVariablesInGC.GCSmallStep ||
					 Semantics.AssignmentMemoryProtocol.InternalVariablesInRHS.RHSSmallStep]
			VariableAssignments?
				[Semantics.AssignmentMemoryProtocol]
				EnvironmentalOutputVariablesInLHS?
				InterfaceVariablesInRHS?
					[Semantics.AssignmentMemoryProtocol.InterfaceVariablesInRHS]
				EnvironmentalInputVariablesInRHS?
			GuardConditions?
				[Semantics.EnablednessMemoryProtocol]
				InterfaceVariablesInGC?
					[Semantics.EnablednessMemoryProtocol.InterfaceVariablesInGC]
				EnvironmentalInputVariablesInGC?

		ControlStates?
			Hierarchical?
				And?
					[Semantics.ConcurrencyAndConsistency]
			Stable?
				[Semantics.BigStepMaximality.Syntactic]
			ComboStable?
				[Semantics.ComboStepMaximality.ComboSyntactic]

	Semantics
		xor BigStepMaximality
			Syntactic
				[Syntax.ControlStates.Stable]
			TakeOne
			TakeMany

		xor ComboStepMaximality ?
			// Need any other combo-step semantic option for this to have meaning:
			[Semantics.EventLifeLine.InternalEvents.PresentInNextComboStep ||
			 Semantics.EventLifeLine.ExternalEvents.ExternalInputEvents.EventOptions.PresentInNextComboStep ||
			 Semantics.EventLifeLine.ExternalEvents.ExternalOutputEvents.EventOptions.PresentInNextComboStep ||
			 Semantics.EnablednessMemoryProtocol.InternalVariablesInGC.GCComboStep ||
			 Semantics.AssignmentMemoryProtocol.InternalVariablesInRHS.RHSComboStep]
			// Options:
			ComboSyntactic
				[Syntax.ControlStates.ComboStable]
			ComboTakeOne
			ComboTakeMany
				[not Semantics.BigStepMaximality.TakeOne]

		ConcurrencyAndConsistency ?
			[Syntax.ControlStates.Hierarchical.And]
			xor Concurrency
				Single
				Many
					xor SmallStepConsistency
						SourceDestinationOrthogonal
						ArenaOrthogonal
					xor Preemption
						NonPreemptive
						Preemptive

		EventLifeLine ?
			[Syntax.Events]
			InternalEvents : EventOptions
			ExternalEvents ?
				ExternalInputEvents ?
					EventOptions : EventOptions
					xor ExternalInputEventOptions
						SyntacticInputEvents
							[Syntax.Events.EventTriggers.EnvironmentalInputEvents]
						ReceivedEventsAsEnvironmental
						HybridInputEvents
				ExternalOutputEvents ?
					EventOptions : EventOptions
					xor ExternalOutputEventOptions
						SyntacticOutputEvents
							[Syntax.Events.GeneratedEvents.EnvironmentalOutputEvents]
						LastComboStepGeneratedEvents
						LastSmallStepGeneratedEvents
						HybridOutputEvents
			xor InterfaceEvents ?
				[Syntax.Events.EventTriggers.InterfaceEvents]
				StrongSynchronousEvent
				WeakSynchronousEvent
				AsynchronousEvent

		EnablednessMemoryProtocol ?
			[Syntax.Variables.GuardConditions]
			xor InternalVariablesInGC
				GCBigStep
				GCSmallStep
				GCComboStep
			xor InterfaceVariablesInGC ?
				[Syntax.Variables.GuardConditions.InterfaceVariablesInGC]
				GCStrongSynchronousVariable
				GCWeakSynchronousVariable
				GCAsynchronousVariable

		AssignmentMemoryProtocol ?
			[Syntax.Variables.VariableAssignments]
			xor InternalVariablesInRHS
				RHSBigStep
				RHSSmallStep
				RHSComboStep
			xor InterfaceVariablesInRHS ?
				[Syntax.Variables.VariableAssignments.InterfaceVariablesInRHS]
				RHSStrongSynchronousVariable
				RHSWeakSynchronousVariable
				RHSAsynchronousVariable

		xor OrderOfSmallSteps ?
			None
			ExplicitOrdering
			Dataflow
				[Syntax.Variables.VariableOperators.new]

		Priority ?
			Hierarchical?
				[Syntax.ControlStates.Hierarchical]
			ExplicitPriority?
			NegationOfTriggers?
				[Syntax.Events.EventTriggers.NegatedEvents ||
				 Syntax.Events.EventTriggers.InterfaceEvents.NegatedInterfaceEvents ||
				 Syntax.Events.EventTriggers.EnvironmentalInputEvents.NegatedEnvironmentalnputEvents]


// Let's say in SCCD, we always have a minimum of syntactic features
SCCD : BSML
	[Syntax.Events]
	[Syntax.ControlStates.Hierarchical.And]
	[Syntax.Variables.VariableAssignments]
	[Syntax.Variables.GuardConditions]

currentlySupported : SCCD
	[PresentInNextSmallStep || PresentInNextComboStep]
	[SyntacticInputEvents]
	[SyntacticOutputEvents]

// validConfiguration : BSML
// 	[PresentInSame]
// 	[ComboTakeMany]

// invalidConfiguration : BSML
// 	[PresentInSame]
// 	[not Concurrency]