We compute the
Poincare polynomial of the quotient of the ambient ring by an ideal.
i1 : R = ZZ/101[w..z];
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i2 : I = monomialCurveIdeal(R,{1,3,4});
o2 : Ideal of R
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i3 : poincare I
2 3 4 5
o3 = 1 - T - 3T + 4T - T
o3 : ZZ [T, MonomialOrder => RevLex, Inverses => true]
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i4 : numerator reduceHilbert hilbertSeries I
2 3
o4 = 1 + 2T + 2T - T
o4 : ZZ [T, MonomialOrder => RevLex, Inverses => true]
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Recall that the variables of the polynomial are the variables of the degrees ring.
i5 : R=ZZ/101[x, Degrees => {{1,1}}];
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i6 : I = ideal x^2;
o6 : Ideal of R
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i7 : poincare I
2 2
o7 = 1 - T T
0 1
o7 : ZZ [T , T , MonomialOrder => RevLex, Inverses => true]
0 1
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i8 : numerator reduceHilbert hilbertSeries I
o8 = 1 + T T
0 1
o8 : ZZ [T , T , MonomialOrder => RevLex, Inverses => true]
0 1
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