case INTCAST : return cache(castExpr, Expression.INTS.accept(this));
case BITSETCAST :
final BooleanFactory factory = super.interpreter.factory();
ret = factory.matrix(Dimensions.square(super.interpreter.universe().size(), 1));
final IntSet ints = super.interpreter.ints();
final int msb = factory.bitwidth()-1;
// handle all bits but the sign bit
for(int i = 0; i < msb; i++) {
int pow2 = 1<<i;
if (ints.contains(pow2)) {
ret.set(super.interpreter.interpret(pow2), BooleanConstant.TRUE);