h.curmod

来自「强大的数学工具包」· CURMOD 代码 · 共 39 行

                               * * * * * * *
                               *   curmod  *
                               * * * * * * *

        "current modulus"
        SYNTAX: X = curmod(m)

        m is an expression whose value is an integer greater 
        than 1.

        curmod specifies the current modulus m. Elements of the
        residue class ring Z/mZ are entered and displayed by the
        symbol 'MOD'. For more information please type "? MOD".
        m is stored in the variable curModulus.
        X is assigned the value of m.

        Remarks: 
        1) If the current modulus p is changed using the function
           curmod, curves over Z/pZ which would be singular over 
           the new modulus are transformed into elliptic curves 
           over Q. 
        2) If the current modulus p is changed using the function
           curmod and the new modulus q is not a prime, elliptic 
           curves and points on elliptic curves over Z/pZ are 
           transformed into elliptic curves and points over Q.
           Warning: If q > 2^30, the primality of q is not tested.
        

        Example 1: (correct)

                curmod(17)


        Example 2: (incorrect)

                curmod(x^3 + 4)

_ERR_NR_156