Open ppurka opened 11 years ago
Description changed:
---
+++
@@ -7,3 +7,58 @@
R = H(x*y)
L == R
+Another example with a segmentation fault. + +``` +F.<x,y> = FreeGroup() +r = x^2*y^-3 +H = F.quotient([r]) +H(r) == H.one_element() + +Traceback (most recent call last):
In general, that is an undecidable problem, so it is not surprising that we don't get an answer.
In some cases there are some things that could be done, like trying to get a normal form (by using rewriting systems, or automatic structures), or symmetric representations (if the group is finite). But again, these methods will only work for some groups, and in general we cannot know in advance if they will work for a given group, so it is not advisable to implement these methods as a general way to compare words. We will have to live with the fact that finitely presented groups present this kind of undecidable problems.
When/if we get kbmag to work under libgap, we could be able to compute automatic structures for FP groups, which would work in this particular example (but not in general).
The following never finishes.
Another example with a segmentation fault.
Depends on #12339
CC: @vbraun
Component: group theory
Issue created by migration from https://trac.sagemath.org/ticket/14025