On Fri, Sep 11, 2015 at 10:48:19PM +0200, aitor_czr wrote: > A * (1/A) = 1 = (1/A) * A > > So, it must be square :-) >
I will become pedantic now, but if A is a matrix, the interpretation of the equations above depends on what "1" and "/" actually mean for you. In general, 1/A does not mean anything when you deal with matrices. The symbol "A^{-1}" is normally used to denote the inverse of A. And the inverse is defined only for square matrices. Hence your "conclusion" is actually a fundamental hypothesys to make those equations mean anything at all :) HND KatolaZ -- [ Enzo Nicosia aka KatolaZ --- GLUG Catania -- Freaknet Medialab ] [ me [at] katolaz.homeunix.net -- http://katolaz.homeunix.net -- ] [ GNU/Linux User:#325780/ICQ UIN: #258332181/GPG key ID 0B5F062F ] [ Fingerprint: 8E59 D6AA 445E FDB4 A153 3D5A 5F20 B3AE 0B5F 062F ] _______________________________________________ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng