Re: Incomplete simplification

*To*: mathgroup at smc.vnet.net*Subject*: [mg49293] Re: Incomplete simplification*From*: BobHanlon at aol.com*Date*: Mon, 12 Jul 2004 02:11:34 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

Simplify works with this on my version $Version 5.0 for Mac OS X (November 19, 2003) S={{0,-x31,x21},{x31,0,-x11},{-x21,x11,0},{0,-x32,x22},{x32,0,-x12},{-x22,x12, 0}}; G=PseudoInverse[S]; G1=Simplify[G, Element[Cases[S, _Symbol,Infinity], Reals]]; G2=ComplexExpand[G]; G1==G2 // Simplify True Bob Hanlon > In a message dated Sun, 11 Jul 2004 06:26:30 +0000 (UTC), > carlos at colorado.edu writes:<BR><BR>Using Mathematica 4.2 on a mac I defined a 6 x 3 > symbolic > matrix and take its Moore-Penrose inverse: > > S={{0,-x31,x21},{x31,0,-x11},{-x21,x11,0},{0,-x32,x22}, > {x32,0,-x12},{-x22,x12,0}}; > G=PseudoInverse[S]; > > Mathematica thinks the entries are complex, so it returns a > result with Conjugate[x11], etc. To get rid of them I tried > > G=Simplify[G,x11\[Element]Reals&&x21\[Element]Reals <...> ]; > > But the Conjugate[...] are still there. Fortunately G=ComplexExpand[G] > works. But why is Simplify unable to use the reality assumptions? >