>We cannot be satisfied with returning wrong answers in the meantime, however. I support Nathann's position.
> Returning 'Unknown' instead of nonsense would be a good first step. I disagree. That Unknown class/object should not be comparable/convertible to True/False, especially if not Unknown if Unknown if Unknown == True if Unknown == False should fail otherwise developers will introduce tons of bugs like if not bool(sin(x) <= 100+cos(x)) : ... And it does not fail: sage: Unknown ==True False sage: Unknown ==False False sage: Unknown ==Unknown True sage: not Unknown True @Volker > Its just behaving as specified, False means "cannot decide" I find, this was a pretty unfortunate specification. I think it would be kind of ok in case 'bool()' would be named 'Holds_If_True_Otherwise_Unknown()' instead Jakob Am Dienstag, 12. Mai 2015 16:02:51 UTC+2 schrieb Nathann Cohen: > > > I think Nils explained the situation pretty well. Making max/min be > > "mathematical" would definitely require some nontrivial effort. > > Why? 'max_symbolic' and 'min_symbolic' already do the job, don't they? > > > I don't > > know that I'm in favor of adding a third boolean option, > > http://www.sagemath.org/doc/reference/misc/sage/misc/unknown.html > > > though of course > > Maxima has various outcomes for e.g. limits. But again, doing that > properly > > would require pretty substantial work. > > We cannot be satisfied with returning wrong answers in the meantime, > however. > > sage: bool(sin(x) <= 100+cos(x)) > False > > Returning 'Unknown' instead of nonsense would be a good first step. > > Nathann > -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
