The were not and never cancel out, so remove the negation. The subjective asserts the horse thing was necessary, not merely sufficient, so be sure there is no c

The were not and never cancel out, so remove the negation. The subjective asserts the horse thing was necessary, not merely sufficient, so be sure there is no college in the other branch. Also throw on some asserts as the non-horse non-college possible world is not the real one. In other words, imperative pseudo-code is a poor substitute for some temporal and possible-world modal logic.