Thanks.But I am afraid that I have not time to read seemingly interesting paper. In stead, just in case, I put the recent codes on compare_with_stack/3 and codes on computing maximum bisimulation on flat terms, which is strongly influenced by P.Aczel’ books, in particular, his final coagebra theorem in ZFC, though it is another story. This codes uses when/2, which I would like to hope it is a typical useful cases for students using freeze/2, which I learned from A. Colmerauer.
compare-with-stack.pl (7.2 KB)