@O@<IllegalConnections.head@>@{@-
#define UNSET 0
#define STATE 1
#define TRANSITION 0
@}

@O@<IllegalConnections.pdl@>@{@-
Kind: int;
@}

@O@<IllegalConnections.check.sl@>@{@-

SYMBOL State COMPUTE
    SYNT.KindOk = ResetKind(THIS.Key, STATE);
END;

SYMBOL Transition COMPUTE
    SYNT.KindOk = ResetKind(THIS.Key, TRANSITION);
END;

SYMBOL PetriNet COMPUTE
    SYNT.KindOk = CONSTITUENTS (Transition.KindOk, State.KindOk);
END;

SYMBOL Connection: fromKind, toKind: int;
SYMBOL Connection: illegalConnection: int;

SYMBOL Connection COMPUTE
    SYNT.fromKind = GetKind(THIS.StartKey, UNSET)
	<- INCLUDING PetriNet.KindOk;
    SYNT.toKind = GetKind(THIS.EndKey, UNSET)
	<- INCLUDING PetriNet.KindOk;
    
    SYNT.illegalConnection = 
	AND(EQ(THIS.fromKind, THIS.toKind), NE(THIS.fromKind, UNSET));

    IF (THIS.illegalConnection,
        message(ERROR, "IllegalConnection", 0, _currn));
END;

@}