-- -*- M2-comint -*- {* hash: -1398602193 *} i1 : R = ZZ/101[a..h] o1 = R o1 : PolynomialRing i2 : p = genericMatrix(R,a,2,4) o2 = | a c e g | | b d f h | 2 4 o2 : Matrix R <--- R i3 : q = generators gb p o3 = | g e c a 0 0 0 0 0 0 | | h f d b fg-eh dg-ch bg-ah de-cf be-af bc-ad | 2 10 o3 : Matrix R <--- R i4 : C = resolution cokernel leadTerm q 2 10 14 7 1 o4 = R <-- R <-- R <-- R <-- R <-- 0 0 1 2 3 4 5 o4 : ChainComplex i5 : betti C 0 1 2 3 4 o5 = total: 2 10 14 7 1 0: 2 4 6 4 1 1: . 6 8 3 . o5 : BettiTally i6 : R = QQ[a,b,c,Degrees=>{-1,-2,-3}]; i7 : heft R o7 = {-1} o7 : List i8 : betti res coker vars R 0 1 2 3 o8 = total: 1 3 3 1 0: 1 1 . . 1: . 1 1 . 2: . 1 1 . 3: . . 1 1 o8 : BettiTally i9 : betti(oo, Weights => {1}) 0 1 2 3 o9 = total: 1 3 3 1 -9: . . . 1 -8: . . . . -7: . . 1 . -6: . . 1 . -5: . . 1 . -4: . 1 . . -3: . 1 . . -2: . 1 . . -1: . . . . 0: 1 . . . o9 : BettiTally i10 : R = QQ[a,b,c,d,Degrees=>{{1,0},{2,1},{0,1},{-2,1}}]; i11 : heft R o11 = {1, 3} o11 : List i12 : b = betti res coker vars R 0 1 2 3 4 o12 = total: 1 4 6 4 1 0: 1 2 1 . . 1: . . . . . 2: . 1 2 1 . 3: . . . . . 4: . 1 2 1 . 5: . . . . . 6: . . 1 2 1 o12 : BettiTally i13 : betti(b, Weights => {1,0}) 0 1 2 3 4 o13 = total: 1 4 6 4 1 -4: . . 1 1 . -3: . 1 1 1 1 -2: . . 1 1 . -1: . 1 1 . . 0: 1 1 1 1 . 1: . 1 1 . . o13 : BettiTally i14 : betti(b, Weights => {0,1}) 0 1 2 3 4 o14 = total: 1 4 6 4 1 -1: . 1 3 3 1 0: 1 3 3 1 . o14 : BettiTally i15 :