On Wed, 7 Jun 2017 18:26:47 +0200, Jan Rheinländer <jrheinlaender@gmx.de> said:
JR> Hi, I'm wondering what is going on here (ginsh output): >> subs($1 * x + 1/2 * x^2 * $2, match(a * x + b, $1 + x * $2)); JR> b*a+1/2*a^3 JR> What happened to "x" ? The match by itself correctly finds >> match(a * x + b, $1 + x * $2); JR> {$2==a,$1==b} JR> but the substitution result is weird. According to the GiNaC tutorial: "* A single wildcard matches any expression. " Thus, the wildcard $2 matches to x, then the expression $1 * $2 + 1/2 * $2^2 * $2 is substituted using {$2==a,$1==b}. -- Vladimir V. Kisil http://www.maths.leeds.ac.uk/~kisilv/ Book: Geometry of Mobius Transformations http://goo.gl/EaG2Vu Software: Geometry of cycles http://moebinv.sourceforge.net/