> > What you could do is to install your own, method for \= (equality) for > elements of fp group (the standard method is in line 164 of lib/grpfp.gi, > you could just start from this method and modify it. If you read it in > later it will rank higher than the library method) that would not only test > for equality of the word expressions, but also checks -- if > HasFpElementEquatityMethod(FamilyObj(left))-=false, i.e. no good equality > test exists yet -- > whether the word is equal to any of the relators (or products, inverses, > conjugates, etc.) This quickly will get more complicated than you might > have hoped for, and you need to decide for a good heuristic how far you > consider a consequence from relators as "obvious" (e.g. in your example, > what if G has the relator (xy^4y^5x^4y^-5(xy)^2 instead while H is the > same?) >
Okay -- this is what I expected the answer to be, but I wanted to be sure before I hand-coded something. I have a heuristic in mind that would cover many of the cases that come up for me in practice -- namely, that G has relators [w_1^a_1, ..., w_k^a_k], and H has at least the relators [w_1^b_1, ..., w_k^b_k] with each b_i dividing a_i. In this case, I can tell at a glance that G covers H, and I just want for GAP to be as fast as I am :) Thanks! (And thanks for moving the message to the right place -- I was a little fuzzy on where a question like this should go.) Gabe _______________________________________________ Forum mailing list Forum@gap-system.org https://mail.gap-system.org/mailman/listinfo/forum
