From: SourceForge.net <noreply@so...>  20040127 14:20:30

Bugs item #875102, was opened at 20040111 16:43 Message generated for change (Comment added) made by macrakis You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=875102&group_id=4933 Category: None Group: None Status: Open Resolution: None Priority: 5 Submitted By: Barton Willis (willisbl) Assigned to: Nobody/Anonymous (nobody) Summary: integrands involving false Initial Comment: When ?defint isn't able to find the value of a definite integral, it returns false, and it's the job of $defint to return a correct noun form. Maxima allows false to be used as an identifer  this allows $defint to get mixed up; for example (C1) defint(false,x,0,1); (D1) 'INTEGRATE(FALSE,x,0,1) (C2) defint(false,x,0,2); (D2) 2*FALSE (C3) build_info(); Maxima version: 5.9.0 Maxima build date: 19:10 2/9/2003 host type: i686pcmingw32 lispimplementationtype: Kyoto Common Lisp lispimplementationversion: GCL25.0 This bug may not be worth fixing; it might be better to disallow true, false, und, ... to be used this way. Barton  >Comment By: Stavros Macrakis (macrakis) Date: 20040125 14:11 Message: Logged In: YES user_id=588346 The true/false and ind/und/inf cases are different. integrate(true,...) doesn't make sense, because true is a boolean constant, and there is no good reason to arbitrarily convert boolean functions to real functions (e.g. false=0). So either a noun form or an error or even (ba)*true seem like perfectly OK (non)results. Sure, it would be nice if it were perfectly consistent, but.... The ind/und/inf cases, on the other hand, are not even Integrate issues. Integrate(nnn,x,a,b) where nnn is one of those is = (ba)*nnn. If the simplifier gets that right, then Integrate will get that right. So integrate(inf,a,0,1)=>inf, integrate(inf,a,0,0)=inf*0=und, integrate(ind,a,0,1) =ind*1=ind, integrate(ind,a,0,0)=ind*0=0, integrate (ind,a,0,inf)=ind*inf=und, etc. But currently the simplifier does NOT get simplifications involving nonstandard numbers (inf, minf, infinity, ind, und) right.  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=875102&group_id=4933 