rtoy
commented
4 months ago Imported from SourceForge on 2024-07-06 20:29:43 Created by macrakis on 2004-01-25 19:11:55 Original: https://sourceforge.net/p/maxima/bugs/488/#246c
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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 (b-a)*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 = (b-a)*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 non-standard numbers (inf, minf, infinity, ind, und) right.
Imported from SourceForge on 2024-07-06 20:29:42 Created by willisbl on 2004-01-11 21:43:23 Original: https://sourceforge.net/p/maxima/bugs/488
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: i686-pc-mingw32 lisp-implementation-type: Kyoto Common Lisp lisp-implementation-version: GCL-2-5.0
This bug may not be worth fixing; it might be better to disallow true, false, und, ... to be used this way.
Barton