> Did you mean 'unless' ? Yes. It's a bug. :( Fixed. BTW, often this.Solver.IsTopLevel is false :(. It often happen when edit macros and if try type not consistent "match" (for example, whit "when" clause with bad expression. Maybe you (or Michal) try fix this bug/problem. It is some compiler issues. But I can't bandstand it :(. Vlad.