blanchet [Sat, 05 Jun 2010 15:59:58 +0200] rev 37345
make Sledgehammer's "add:" and "del:" syntax work better in the presence of aliases;
some of these aliases pop up only after Sledgehammer has converted the formula to CNF, so it can be very confusing to the user who said "add: foo del: bar" that "bar" is used in the end.