On Jun 4, 2008, at 5:05 PM, Gary Furnish wrote: > Errors should not under any circumstances be thrown if bool(x==y) is > inconclusive. It would break half of the code that depends on > symbolics, and would require try blocks around every if statement.
Can you give an example of something that would break? The point is that one wouldn't catch the error--if one is branching on a condition that is undetermined then the error should be propagated upwards. - Robert > > On Wed, Jun 4, 2008 at 5:57 PM, Carl Witty <[EMAIL PROTECTED]> > wrote: >> >> On Jun 4, 4:16 pm, Robert Bradshaw <[EMAIL PROTECTED]> >> wrote: >>> On Jun 4, 2008, at 2:46 PM, Jason Grout wrote: >>> >>>> Of course, bool(some equation) returning False does not necessarily >>>> mean >>>> that the two expressions are not equal; it only means that we >>>> couldn't >>>> prove them to be equal using some simple simplifications. >>> >>>> From the docstring for _nonzero_ from equation.py (used to >>>> implement >>>> bool()): >>> >>>> Return True if this (in)equality is definitely true. Return False >>>> if it >>>> is false or the algorithm for testing (in)equality is inconclusive. >>> >>> Should it throw an error in this case? (Is there a way to know if >>> the >>> result was inconclusive?) >> >> In this thread: http://groups.google.com/group/sage-devel/ >> browse_thread/thread/bcdc671d2791056e/e086a9d59ff4b9ba >> it seems that the consensus was to throw an error here; but nobody >> ever implemented it (or even opened a trac ticket, as far as I know). >> >> Carl >>> >> > > > --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
