On 8/14/06, Chris Sangwin <sangwinc at for.mat.bham.ac.uk> wrote:
> (%i11) false nOR false;
> (%o11) nOR(false,false)
>
> Why does this not also simplify to false?
false nOR false => false in 5.9.3.99rc1. src/matcom.lisp and src/matrun.lisp
were modified recently (2006/04) to return a match-success flag separately
from the rule production (false in this case). Before, those two items were
conflated, so if a rule yielded false, it would be interpreted as a
match failure.
Please try it again with a release candidate and let us know if it
works as expected.
Robert Dodier