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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 .000800537)  #primes = 0 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000023938)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00135134)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00231958)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .0246024)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00173894)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00137531)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00137322)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .000294125)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .000220811)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00021106)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00108117)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00116883)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00157609)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00163854)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00101217)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00140509)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00116946)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00131672)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00143519)  #primes = 0 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000006624)  #primes = 1 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000017446)  #primes = 1 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000005293)  #primes = 2 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000005174)  #primes = 3 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000018571)  #primes = 3 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000005865)  #primes = 4 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000782418)  #primes = 6 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .0000178)  #primes = 6 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .00001633)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .00015617)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000143178)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000517341)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000622206)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000107951)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000089569)  #primes = 6 #prunedViaCodim = 0
  Strategy: Linear            (time .000151335)  #primes = 6 #prunedViaCodim = 0
  Strategy: Linear            (time .000144704)  #primes = 6 #prunedViaCodim = 0
  Strategy: Linear            (time .000621156)  #primes = 6 #prunedViaCodim = 0
  Strategy: Linear            (time .000742448)  #primes = 6 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000005649)  #primes = 7 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000005195)  #primes = 8 #prunedViaCodim = 0
  Strategy: IndependentSet    (time .00000863)  #primes = 9 #prunedViaCodim = 0
  Strategy: IndependentSet    (time .000007313)  #primes = 10 #prunedViaCodim = 0
Converting annotated ideals to ideals and selecting minimal primes... Time taken : .00347586
#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 .000786498)  #primes = 0 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000024954)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00141937)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00246026)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00387801)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00174306)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00145702)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00142031)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .000295295)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .000221748)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .000217581)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00109288)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00130443)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00158543)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00164428)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00101727)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00141123)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00117137)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00132444)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00142708)  #primes = 0 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000006993)  #primes = 1 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000018102)  #primes = 1 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000004827)  #primes = 2 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000005771)  #primes = 3 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000016319)  #primes = 3 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000004947)  #primes = 4 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000761542)  #primes = 6 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000017304)  #primes = 6 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000017495)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000158967)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000147407)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000527767)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000625343)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000109962)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000092307)  #primes = 6 #prunedViaCodim = 0
  Strategy: Linear            (time .000151628)  #primes = 6 #prunedViaCodim = 0
  Strategy: Linear            (time .000144571)  #primes = 6 #prunedViaCodim = 0
  Strategy: Linear            (time .000633547)  #primes = 6 #prunedViaCodim = 0
  Strategy: Linear            (time .000733959)  #primes = 6 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000006263)  #primes = 7 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000005696)  #primes = 8 #prunedViaCodim = 0
  Strategy: Birational        (time .00295931)  #primes = 8 #prunedViaCodim = 0
  Strategy: Birational        (time .0026918)  #primes = 8 #prunedViaCodim = 0
  Strategy: Birational        (time .000118058)  #primes = 8 #prunedViaCodim = 0
  Strategy: Birational        (time .000114176)  #primes = 8 #prunedViaCodim = 0
  Strategy: Linear            (time .000028227)  #primes = 8 #prunedViaCodim = 0
  Strategy: Linear            (time .000027107)  #primes = 8 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000006176)  #primes = 9 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000005988)  #primes = 10 #prunedViaCodim = 0
Converting annotated ideals to ideals and selecting minimal primes... Time taken : .00345043
#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 :