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checkDegrees(...,Strict=>...) -- forces strict equality of degrees

Description

Used with Strict=>false, the default, checkDegrees(N,M) returns (true, deg) if degrees M and degrees N are equal up to a shift d. With Strict => true the degree lists must be equal.

i1 : S = ZZ/101[a,b,Degrees => {{1,0},{0,1}}]

o1 = S

o1 : PolynomialRing
i2 : B = S^{{1,1}}

      1
o2 = S

o2 : S-module, free, degrees {{-1, -1}}
i3 : B' = S^{{3,3}}**B

      1
o3 = S

o3 : S-module, free, degrees {{-4, -4}}
i4 : d = checkDegrees(B',B)

o4 = (true, {-3, -3})

o4 : Sequence
i5 : degrees (S^{d_1}**B') == degrees B

o5 = true
i6 : degrees (B') == degrees (S^{-d_1}**B)

o6 = true
i7 : checkDegrees(B',B,Strict=>true)

o7 = (false, )

o7 : Sequence

See also

Functions with optional argument named Strict:

Further information

  • Default value: false
  • Function: checkDegrees -- compares the degrees of generators of two modules
  • Option key: Strict -- an optional argument

The source of this document is in /build/reproducible-path/macaulay2-1.25.06+ds/M2/Macaulay2/packages/Isomorphism.m2:528:0.