On Monday, March 11, 2019 at 11:05:04 AM UTC-7, Michael Beeson wrote: > > I appreciate Eric's post, and I do use subs sometimes, but it makes me > nervous since > it will happily substitute any old thing you tell it to, even an > incorrect thing. So, if your idea > is to check a computation, it is a dangerous thing. True, if you put > only correct equations in, > you'll usually get correct ones out. >
Checking a result is usually much easier: Take the original form of the equation, subtract the simplified form, and check that the difference is divisible by the relations you impose, such as b^2-(1-a^2). No special normal forms are required, just a divisibility test. This gets more complicated when there are more relations, because then you'll need an ideal membership test, but then you can just present that as "the computational tool" (plus, with a bit of luck you can extract the way in which the difference can be expressed in terms of the generating relations. The algorithm in principle encounters that information on the way) -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at https://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
