12 Mar
1996
12 Mar
'96
10:11 p.m.
Michael Barr's reply to this question was not entirely complete (IMHO), as he forgot to mention that he wrote a short paper some time (3 yrs) ago dealing with matters related to this. Those interested might want to download his paper, which can be obtained by ftp from triples.math.mcgill.ca in the directory pub/barr (look for variable.sets.*.Z, where * = dvi, tex, or ps). = rags =