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D.2.3.20 factorH

Procedure from library general.lib (see general_lib).

Usage:
factorH(p) p poly

Return:
factorize(p)

Note:
changes variables to make the last variable the principal one in the multivariate factorization and factorizes then the polynomial

Example:
 
LIB "general.lib";
system("random",992851144);
ring r=32003,(x,y,z,w,t),lp;
poly p=y2w9+yz7t-yz5w4-z2w4t4-w8t3;
factorize(p);  //fast
==> [1]:
==>    _[1]=-1
==>    _[2]=-y2w9-yz7t+yz5w4+z2w4t4+w8t3
==> [2]:
==>    1,1
system("random",992851262);
//factorize(p);  //slow
system("random",992851262);
factorH(p);
==> [1]:
==>    _[1]=1
==>    _[2]=y2w9+yz7t-yz5w4-z2w4t4-w8t3
==> [2]:
==>    1,1