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D.2.3.21 factorH
Procedure from librarygeneral.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
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
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