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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 .00123911)  #primes = 0 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000037173)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00202311)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00304012)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00468038)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00210589)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00164115)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00171387)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .000317389)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .000225287)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .000220526)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .0014485)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .0016793)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00216769)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00250414)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00144421)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .0019571)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00167356)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00180342)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00190987)  #primes = 0 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000007118)  #primes = 1 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000031258)  #primes = 1 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000005943)  #primes = 2 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000006698)  #primes = 3 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .00002209)  #primes = 3 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000005944)  #primes = 4 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .00147165)  #primes = 6 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000024187)  #primes = 6 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000022074)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000204617)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000177952)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000644416)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000736386)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000120067)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000092227)  #primes = 6 #prunedViaCodim = 0
  Strategy: Linear            (time .000216682)  #primes = 6 #prunedViaCodim = 0
  Strategy: Linear            (time .00019837)  #primes = 6 #prunedViaCodim = 0
  Strategy: Linear            (time .00167483)  #primes = 6 #prunedViaCodim = 0
  Strategy: Linear            (time .000981017)  #primes = 6 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000007364)  #primes = 7 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000007127)  #primes = 8 #prunedViaCodim = 0
  Strategy: IndependentSet    (time .000013216)  #primes = 9 #prunedViaCodim = 0
  Strategy: IndependentSet    (time .000009941)  #primes = 10 #prunedViaCodim = 0
Converting annotated ideals to ideals and selecting minimal primes... Time taken : .00404344
#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 .00111929)  #primes = 0 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000033156)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00183412)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .013291)   #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .01527)    #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00222561)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00750026)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .00175575)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .000333452)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .000226121)  #primes = 0 #prunedViaCodim = 0
  Strategy: Factorization     (time .000219692)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .16209)    #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00176942)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00257944)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00227993)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .0309309)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .0256724)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00165587)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00182335)  #primes = 0 #prunedViaCodim = 0
  Strategy: Linear            (time .00193925)  #primes = 0 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000007277)  #primes = 1 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000022536)  #primes = 1 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000006761)  #primes = 2 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000005945)  #primes = 3 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000021124)  #primes = 3 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000007129)  #primes = 4 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .00103794)  #primes = 6 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000021829)  #primes = 6 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000020751)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000224822)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .00018034)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000658442)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000751781)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000119764)  #primes = 6 #prunedViaCodim = 0
  Strategy: Factorization     (time .000092193)  #primes = 6 #prunedViaCodim = 0
  Strategy: Linear            (time .0002205)  #primes = 6 #prunedViaCodim = 0
  Strategy: Linear            (time .00020982)  #primes = 6 #prunedViaCodim = 0
  Strategy: Linear            (time .000854115)  #primes = 6 #prunedViaCodim = 0
  Strategy: Linear            (time .000963813)  #primes = 6 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000005902)  #primes = 7 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .00000618)  #primes = 8 #prunedViaCodim = 0
  Strategy: Birational        (time .00638694)  #primes = 8 #prunedViaCodim = 0
  Strategy: Birational        (time .00401841)  #primes = 8 #prunedViaCodim = 0
  Strategy: Birational        (time .000194187)  #primes = 8 #prunedViaCodim = 0
  Strategy: Birational        (time .000284562)  #primes = 8 #prunedViaCodim = 0
  Strategy: Linear            (time .00004788)  #primes = 8 #prunedViaCodim = 0
  Strategy: Linear            (time .000044331)  #primes = 8 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000009491)  #primes = 9 #prunedViaCodim = 0
  Strategy: DecomposeMonomials(time .000013064)  #primes = 10 #prunedViaCodim = 0
Converting annotated ideals to ideals and selecting minimal primes... Time taken : .00437682
#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 :