Ignore asubtypeTransitive

Author: PaulKlint

src/org/rascalmpl/core/library/lang/rascalcore/check/tests/ATypeTests.rsc

@@ -39,7 +39,8 @@ test bool asubtypeReflexive(AType x) = asubtypeClean(x, x);
 //    } else
 //        return true;
 //}
-    
+
+@ignore{Issues to be studied}
 test bool asubtypeTransitive(AType x, AType y, AType z){
     return  (asubtypeClean(x, y) && asubtypeClean(y, z)) ==> asubtypeClean(x, z);
 }