restrictedRanks -- display the ranks of an OI-resolution restricted to a given width

Synopsis

Given an OI-resolution $C$ and a width $w$, this method displays the ranks of the modules in $C$ restricted to width $w$.

i1 : P = makePolynomialOIAlgebra(2, x, QQ);

i2 : F = makeFreeOIModule(e, {1,1}, P);

i3 : installGeneratorsInWidth(F, 2);

i4 : b = x_(1,2)*x_(1,1)*e_(2,{2},1)+x_(2,2)*x_(2,1)*e_(2,{1},2);

i5 : C = oiRes({b}, 2)

o5 = 0: (e0, {2}, {-2})
     1: (e1, {4}, {-4})
     2: (e2, {5, 5, 5}, {-5, -5, -5})

o5 : OIResolution

i6 : ranks C

o6 = 0: rank 1
     1: rank 1
     2: rank 3

i7 : restrictedRanks(C,5)

o7 = 0: rank 10
     1: rank 5
     2: rank 3