`modfctr'
---------

modfctr(POLY,MOD)
     :: Univariate factorizer over small finite fields

RETURN
     list

POLY
     univariate polynomial with integer coefficients

MOD
     non-negative integer

   * This function factorizes a univarate polynomial POLY over the
     finite prime field of characteristic MOD, where MOD must be
     smaller than 2^31.

   * The result is represented by a list, whose elements are a pair
     represented as

     [[num,1],[factor,multiplicity],...].

   * Products of all factor^multiplicity and num is equal to POLY.

   * To factorize polynomials over large finite fields, use `fctr_ff'
     (*note Finite fields::,*Note fctr_ff::).

     [0] modfctr(x^10+x^2+1,2147483647);
     [[1,1],[x+1513477736,1],[x+2055628767,1],[x+91854880,1],
     [x+634005911,1],[x+1513477735,1],[x+634005912,1],
     [x^4+1759639395*x^2+2045307031,1]]

References
     *Note `fctr sqfr': fctr sqfr.

