Hello, I have updated the polynomial package over GiNaC, especially factorization: ftp://fourier.ujf-grenoble.fr/pub/hp48/giac.tgz Main changes: * 2 version are available: you can either use giac with the NTL univariate factorization library or standalone * the code is faster. Installation requires gmp, cln and GiNaC, optionnaly NTL. Some timimgs of the standalone version on a Celeron 533 Mhz (# Time 0 means <=0.01 sec) (c+x+b)*(b^2-c*x+x^2-c*b+c^2-x*b) # Time0 (x+y+z)*(x-y+z)*(x-y-z) # Time0.01 (-5+3*x+y-y^2)*(-1+3*x+x*y-y^2) # Time0.01 (x-3*y+y*z)*(2*x-z+x*y)*(1+x*z+x*y+6*x^3) # Time0.02 (x*y+y^2+x^2)*(-x*y+y^2+x^2)*(x-y)*(-x-y) # Time0.01 (2+x^3+13*x*y*z^2-21*x*y^3*z)*(1+x*z+x*y+6*x^3) # Time0.01 2+x^3+13*x*y*z^2-21*x*y^3*z # Time0.01 x^2*y^2*(-x+y)*z^5*(-x-y-z) # Time0.01 -x^3*y^2*z*(x-y-z)*(-x+y-z)*(-x-y-z) # Time0.01 (8+15*x)*(1+8*x)*(11+5*x)*(-31+30*x)*(-13+12*x)*(-209+120*x) # Time0.01 (1+x^5+x^20+x^10+x^15)*(1-x^5+x^20+x^10-x^15) # Time0.02 (1+x^35+x^5-x^20+x^40-x^25-x^15)*(1-x^35-x^5-x^20+x^40+x^25+x^15)*(1+x-x^4+x^8-x^5-x^3+x^7)*(1-x-x^4+x^8+x^5+x^3-x^7)*(1+x+x^2)*(1-x+x^2) # Time0.13 If you are factoring big polynomials, the NTL version should be used instead of the standalone version (since it does not include e.g. FFT polynomial multiplication ...) Bernard Parisse