/usr/share/axiom-20170501/src/algebra/MONOTOOL.spad is in axiom-source 20170501-3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 | )abbrev package MONOTOOL MonomialExtensionTools
++ Author: Manuel Bronstein
++ Date Created: 18 August 1992
++ Date Last Updated: 3 June 1993
++ Description: 
++ Tools for handling monomial extensions.
MonomialExtensionTools(F, UP) : SIG == CODE where
  F : Field
  UP : UnivariatePolynomialCategory F
  RF ==> Fraction UP
  FR ==> Factored UP
  SIG ==> with
    split : (UP, UP -> UP) -> Record(normal:UP, special:UP)
      ++ split(p, D) returns \spad{[n,s]} such that \spad{p = n s},
      ++ all the squarefree factors of n are normal w.r.t. D,
      ++ and s is special w.r.t. D.
      ++ D is the derivation to use.
    splitSquarefree : (UP, UP -> UP) -> Record(normal:FR, special:FR)
      ++ splitSquarefree(p, D) returns
      ++ \spad{[n_1 n_2\^2 ... n_m\^m, s_1 s_2\^2 ... s_q\^q]} such that
      ++ \spad{p = n_1 n_2\^2 ... n_m\^m s_1 s_2\^2 ... s_q\^q}, each
      ++ \spad{n_i} is normal w.r.t. D and each \spad{s_i} is special
      ++ w.r.t D.
      ++ D is the derivation to use.
    normalDenom : (RF, UP -> UP) -> UP
      ++ normalDenom(f, D) returns the product of all the normal factors
      ++ of \spad{denom(f)}.
      ++ D is the derivation to use.
    decompose  : (RF, UP -> UP) -> Record(poly:UP, normal:RF, special:RF)
      ++ decompose(f, D) returns \spad{[p,n,s]} such that \spad{f = p+n+s},
      ++ all the squarefree factors of \spad{denom(n)} are normal w.r.t. D,
      ++ \spad{denom(s)} is special w.r.t. D,
      ++ and n and s are proper fractions (no pole at infinity).
      ++ D is the derivation to use.
  CODE ==> add
    normalDenom(f, derivation) == split(denom f, derivation).normal
    split(p, derivation) ==
      pbar := (gcd(p, derivation p) exquo gcd(p, differentiate p))::UP
      zero? degree pbar => [p, 1]
      rec := split((p exquo pbar)::UP, derivation)
      [rec.normal, pbar * rec.special]
    splitSquarefree(p, derivation) ==
      s:Factored(UP) := 1
      n := s
      q := squareFree p
      for rec in factors q repeat
        r := rec.factor
        g := gcd(r, derivation r)
        if not ground? g then s := s * sqfrFactor(g, rec.exponent)
        h := (r exquo g)::UP
        if not ground? h then n := n * sqfrFactor(h, rec.exponent)
      [n, unit(q) * s]
    decompose(f, derivation) ==
      qr := divide(numer f, denom f)
      -- rec.normal * rec.special = denom f
      rec := split(denom f, derivation)
      -- eeu.coef1 * rec.normal + eeu.coef2 * rec.special = qr.remainder
      -- and degree(eeu.coef1) < degree(rec.special)
      -- and degree(eeu.coef2) < degree(rec.normal)
      -- qr.remainder/denom(f)=eeu.coef1 / rec.special + eeu.coef2 / rec.normal
      eeu := extendedEuclidean(rec.normal, rec.special,
                               qr.remainder)::Record(coef1:UP, coef2:UP)
      [qr.quotient, eeu.coef2 / rec.normal, eeu.coef1 / rec.special]
 |