run ins.als

get:

bash-2.05$ java -classpath alloy/bin alloy.RunAlloy ins.als 
Alloy Analyzer version 2.0
Run with -h option for help
Questions to alloy-support@mit.edu

processing ins.als...
java.util.NoSuchElementException
	at java.util.AbstractList$Itr.next(Unknown Source)
	at alloy.transform.TypeConstraints.createUnionExpr(TypeConstraints.java:440)
	at alloy.transform.TypeConstraints.addConstraintsForSig(TypeConstraints.java:144)
	at alloy.transform.TypeConstraints.createTypeConstraints(TypeConstraints.java:56)
	at alloy.transform.GenCommandFormulasVisitor.visit(GenCommandFormulasVisitor.java:36)
	at alloy.ast.Specification.acceptVisitor(Specification.java:78)
	at alloy.ast.TreeNode.applyVisitor(TreeNode.java:305)
	at alloy.RunAlloy.performElaborations(RunAlloy.java:125)
	at alloy.RunAlloy.run(RunAlloy.java:84)
	at alloy.RunAlloy.main(RunAlloy.java:74)


FIX: bug in alloy.parse.MakeASTVisitor with handling disjoint sigs.  we still
need to do a general fix to our handling of this problem.