h.f1root

来自「强大的数学工具包」· F1ROOT 代码 · 共 43 行

                         * * * * * * *
                         *   f1root  *
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        "finding one root"
        SYNTAX: X = f1root(p,P)
                X = f1root(Q)

        p is an expression whose value is a prime.
        In the first case, P is a univariate polynomial over Z.
        In the second case, Q is a univariate polynomial over
        Z/pZ, where p is a prime, or over GF(p^n).

        In the first case, froot computes one root of P over Z/pZ. 
        In the second case, froot computes one root of Q over Z/pZ
        or over GF(p^n).
        X is assigned this root of P (or Q), if there exists one.


        Warning: If p > 2^30, the primality of p is not tested.


        Example 1: (correct)

                f1root(5,x^2+1)


        Example 2: (correct)

                f1root(MOD(x^3+2*x+1))


        Example 3: (correct)

                f1root(GF(A*x^3+x^2+A^4+3))


        Example 4: (incorrect)

                f1root(x^4-2)

_ERR_NR_321