incorrect reference refinement check

[mantkiew]

For a correct model

abstract ASIL -> integer
A : ASIL -> 1
B : ASIL -> 2
C : ASIL -> 3
D : ASIL -> 4

I am getting an error

Unhandled compilation error occured. Please report this problem.
Wrapped java.lang.IllegalArgumentException: c0_A cannot refine reference uniqueness

The model actually refines the references correctly and it currently works in AlloyIG:

D -> 4
C -> 3
B -> 2
A -> 1

[JLiangWaterloo]

Here is the javascript file:

scope({c0_ASIL:4});
defaultScope(1);
intRange(-8, 7);
stringLength(16);

c0_ASIL = Abstract("c0_ASIL");
c0_A = Clafer("c0_A").withCard(1, 1);
c0_B = Clafer("c0_B").withCard(1, 1);
c0_C = Clafer("c0_C").withCard(1, 1);
c0_D = Clafer("c0_D").withCard(1, 1);
c0_ASIL.refToUnique(Int);
c0_A.extending(c0_ASIL).refTo(Int);
c0_B.extending(c0_ASIL).refTo(Int);
c0_C.extending(c0_ASIL).refTo(Int);
c0_D.extending(c0_ASIL).refTo(Int);

So the refinement is stripping away the "uniqueness" property, which is not valid. This is a problem with the Clafer compiler.

[mantkiew]

I created a compiler issue. Does that output make any sense? Or should it be something like

c0_D.extending(c0_ASIL).refToUnique(IntLiteral(1));