normal.cpp, normal.h: Fix Yun's algorithm (there was a mistake in Geddes et
authorRichard Kreckel <Richard.Kreckel@uni-mainz.de>
Sun, 11 Mar 2001 19:10:03 +0000 (19:10 +0000)
committerRichard Kreckel <Richard.Kreckel@uni-mainz.de>
Sun, 11 Mar 2001 19:10:03 +0000 (19:10 +0000)
commitfae800e3a2dfe04b49bac90cfd7ab4e155e865e6
tree5a8e67c8193de6b21571f24cd15d9a8721980614
parente13c691c25abd739163d30de5e6d038977683690
normal.cpp, normal.h: Fix Yun's algorithm (there was a mistake in Geddes et
al.) for square-free factorization.  Also change the syntax to allow for
square-free factoring in a recursive way in Q[X].  This is an example how it
works in Z[x,y,z] in ginsh:
> ?sqrfree
sqrfree(expression [, symbol-list]) - square-free factorization of a polynomial
> sqrfree(expand((x+y)*(x+y+z)^2*(y-z)^3));
(x+y)*(-x-y-z)^2*(y^3+3*y*z^2-3*y^2*z-z^3)
> sqrfree(expand((x+y)*(x+y+z)^2*(y-z)^3),[y]);
(x+y)*(y-z)^3*(x+y+z)^2
> sqrfree(expand((x+y)*(x+y+z)^2*(y-z)^3),[z]);
(x+y)*(y-z)^3*(x+y+z)^2
> sqrfree(expand((x+y)*(x+y+z)^2*(y-z)^3),[x]);
(x+y)*(-x-y-z)^2*(y^3+3*y*z^2-3*y^2*z-z^3)
> sqrfree(expand((x+y)*(x+y+z)^2*(y-z)^3),[x,y]);
(x+y)*(-x-y-z)^2*(y^3+3*y*z^2-3*y^2*z-z^3)
> sqrfree(expand((x+y)*(x+y+z)^2*(y-z)^3),[x,y,z]);
(x+y)*(-x-y-z)^2*(y^3+3*y*z^2-3*y^2*z-z^3)
> sqrfree(expand((x+y)*(x+y+z)^2*(y-z)^3),[v]);
3*x*y^5+3*x^2*y^4+x^3*y^3+y^6-y*z^5-2*y^4*z^2+y^2*z^4-y^5*z+2*y^3*z^3-3*x^3*y^2*z+3*x^3*y*z^2-5*x*y^4*z-x*y*z^4+3*x^2*y*z^3+6*x*y^2*z^3+3*x^2*y^2*z^2-2*x*y^3*z^2-7*x^2*y^3*z-x^3*z^3-2*x^2*z^4-x*z^5
NEWS
ginac/normal.cpp
ginac/normal.h
ginsh/ginsh.1.in
ginsh/ginsh_parser.yy