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MinimalPrimes :: minprimes

minprimes -- minimal primes in a polynomial ring over a field

Synopsis

Description

Given an ideal in a polynomial ring, or a quotient of a polynomial ring whose base ring is either QQ or ZZ/p, return a list of minimal primes of the ideal.

i1 : R = ZZ/32003[a..e]

o1 = R

o1 : PolynomialRing
i2 : I = ideal"a2b-c3,abd-c2e,ade-ce2"

             2     3           2              2
o2 = ideal (a b - c , a*b*d - c e, a*d*e - c*e )

o2 : Ideal of R
i3 : C = minprimes I;
i4 : netList C

     +---------------------------+
o4 = |ideal (c, a)               |
     +---------------------------+
     |              2     3      |
     |ideal (e, d, a b - c )     |
     +---------------------------+
     |ideal (e, c, b)            |
     +---------------------------+
     |ideal (d, c, b)            |
     +---------------------------+
     |ideal (d - e, b - c, a - c)|
     +---------------------------+
     |ideal (d + e, b - c, a + c)|
     +---------------------------+
i5 : C2 = minprimes(I, Strategy=>"NoBirational", Verbosity=>2)
  Strategy: Linear            (time .0013437)  #primes = 0 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000039312)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00242454)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00377739)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00592394)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .0025245)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00200943)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00212422)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .000432182)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00027869)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .000278704)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .0017065)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00203632)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00266074)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .0027711)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00174541)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00235164)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00195909)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00217073)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00233739)  #primes = 0 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000008746)  #primes = 1 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .00002661)  #primes = 1 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000008168)  #primes = 2 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .00000703)  #primes = 3 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000026386)  #primes = 3 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000007152)  #primes = 4 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .00118987)  #primes = 6 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .00002457)  #primes = 6 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000024332)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000266186)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000250248)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000787548)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000952396)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000157976)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000123132)  #primes = 6 #prunedViaCodim = 0
  Strategy: Linear            (time .000266414)  #primes = 6 #prunedViaCodim = 0
  Strategy: Linear            (time .0002481)  #primes = 6 #prunedViaCodim = 0
  Strategy: Linear            (time .000993914)  #primes = 6 #prunedViaCodim = 0
  Strategy: Linear            (time .00114595)  #primes = 6 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000007198)  #primes = 7 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .00000718)  #primes = 8 #prunedViaCodim = 0
  Strategy: IndependentSet    (time .000011364)  #primes = 9 #prunedViaCodim = 0
  Strategy: IndependentSet    (time .000012214)  #primes = 10 #prunedViaCodim = 0
Converting annotated ideals to ideals and selecting minimal primes... Time taken : .00505034
#minprimes=6 #computed=10

                                  2     3
o5 = {ideal (c, a), ideal (e, d, a b - c ), ideal (e, c, b), ideal (d, c, b),
     ------------------------------------------------------------------------
     ideal (d - e, b - c, a - c), ideal (d + e, b - c, a + c)}

o5 : List
i6 : C1 = minprimes(I, Strategy=>"Birational", Verbosity=>2)
  Strategy: Linear            (time .00135474)  #primes = 0 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .00003913)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00239959)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00382463)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00595045)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00256714)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00204568)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00215448)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00043566)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00028366)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .000281702)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00174422)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00211542)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00270455)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00280792)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .0156844)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00240256)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00199455)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00221676)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00232858)  #primes = 0 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000008676)  #primes = 1 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .0000255)  #primes = 1 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000006924)  #primes = 2 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000007314)  #primes = 3 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000024618)  #primes = 3 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000006842)  #primes = 4 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .00119883)  #primes = 6 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000026638)  #primes = 6 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .00002389)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000273082)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000248944)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000798124)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .00092486)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000158794)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000123912)  #primes = 6 #prunedViaCodim = 0
  Strategy: Linear            (time .000262866)  #primes = 6 #prunedViaCodim = 0
  Strategy: Linear            (time .000243308)  #primes = 6 #prunedViaCodim = 0
  Strategy: Linear            (time .00101822)  #primes = 6 #prunedViaCodim = 0
  Strategy: Linear            (time .00113009)  #primes = 6 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000007128)  #primes = 7 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000008192)  #primes = 8 #prunedViaCodim = 0
  Strategy: Birational        (time .00502853)  #primes = 8 #prunedViaCodim = 0
  Strategy: Birational        (time .00444162)  #primes = 8 #prunedViaCodim = 0
  Strategy: Birational        (time .000219808)  #primes = 8 #prunedViaCodim = 0
  Strategy: Birational        (time .000219154)  #primes = 8 #prunedViaCodim = 0
  Strategy: Linear            (time .000052548)  #primes = 8 #prunedViaCodim = 0
  Strategy: Linear            (time .000087126)  #primes = 8 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .00000968)  #primes = 9 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000008518)  #primes = 10 #prunedViaCodim = 0
Converting annotated ideals to ideals and selecting minimal primes... Time taken : .00502786
#minprimes=6 #computed=10

                                  2     3
o6 = {ideal (c, a), ideal (e, d, a b - c ), ideal (e, c, b), ideal (d, c, b),
     ------------------------------------------------------------------------
     ideal (d - e, b - c, a - c), ideal (d + e, b - c, a + c)}

o6 : List

Caveat

This will eventually be made to work over GF(q), and over other fields too.

Ways to use minprimes :