From: SourceForge.net <noreply@so...>  20040409 17:17:42

Bugs item #932395, was opened at 20040409 13:17 Message generated for change (Tracker Item Submitted) made by Item Submitter You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=932395&group_id=4933 Category: None Group: None Status: Open Resolution: None Priority: 5 Submitted By: Stavros Macrakis (macrakis) Assigned to: Nobody/Anonymous (nobody) Summary: solve confused by ratvars Initial Comment: solve(rat(a+c,a,b,c,d),[a,b]) => [[a=%r1, b=%r1]] NO! Remove the extra variable: solve(rat(a+c,a,b,c),[a,b]) => [[a =  c, b = %r2]] OK Also works fine if you call algsys directly: algsys([rat(a+c,a,b,c,d)],[a,b]); At first I thought this had something to do with the variable *ordering* in the first case, but in fact it happens with all orderings. The problem is the number of ratvars. Note that this is *not* an artificial situation. It is common to have CREs with more ratvars than they use after arithmetic operations, e.g. rat(a+b)rat(a).  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=932395&group_id=4933 
From: SourceForge.net <noreply@so...>  20060729 06:12:58

Bugs item #932395, was opened at 20040409 11:17 Message generated for change (Settings changed) made by robert_dodier You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=932395&group_id=4933 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. >Category: Lisp Core Group: None Status: Open Resolution: None Priority: 5 Submitted By: Stavros Macrakis (macrakis) Assigned to: Nobody/Anonymous (nobody) Summary: solve confused by ratvars Initial Comment: solve(rat(a+c,a,b,c,d),[a,b]) => [[a=%r1, b=%r1]] NO! Remove the extra variable: solve(rat(a+c,a,b,c),[a,b]) => [[a =  c, b = %r2]] OK Also works fine if you call algsys directly: algsys([rat(a+c,a,b,c,d)],[a,b]); At first I thought this had something to do with the variable *ordering* in the first case, but in fact it happens with all orderings. The problem is the number of ratvars. Note that this is *not* an artificial situation. It is common to have CREs with more ratvars than they use after arithmetic operations, e.g. rat(a+b)rat(a).  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=932395&group_id=4933 
From: SourceForge.net <noreply@so...>  20060909 01:53:14

Bugs item #932395, was opened at 20040409 11:17 Message generated for change (Settings changed) made by robert_dodier You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=932395&group_id=4933 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. >Category: Lisp Core  Solving equations Group: None Status: Open Resolution: None Priority: 5 Submitted By: Stavros Macrakis (macrakis) Assigned to: Nobody/Anonymous (nobody) Summary: solve confused by ratvars Initial Comment: solve(rat(a+c,a,b,c,d),[a,b]) => [[a=%r1, b=%r1]] NO! Remove the extra variable: solve(rat(a+c,a,b,c),[a,b]) => [[a =  c, b = %r2]] OK Also works fine if you call algsys directly: algsys([rat(a+c,a,b,c,d)],[a,b]); At first I thought this had something to do with the variable *ordering* in the first case, but in fact it happens with all orderings. The problem is the number of ratvars. Note that this is *not* an artificial situation. It is common to have CREs with more ratvars than they use after arithmetic operations, e.g. rat(a+b)rat(a).  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=932395&group_id=4933 