-- -*- M2-comint -*- {* hash: 1392795732 *} i1 : R = QQ[a..z] o1 = R o1 : PolynomialRing i2 : f = genericMatrix(R,3,5) o2 = | a d g j m | | b e h k n | | c f i l o | 3 5 o2 : Matrix R <--- R i3 : M = coker gens minors_3 f o3 = cokernel | -ceg+bfg+cdh-afh-bdi+aei -cej+bfj+cdk-afk-bdl+ael -chj+bij+cgk-aik-bgl+ahl -fhj+eij+fgk-dik-egl+dhl -cem+bfm+cdn-afn-bdo+aeo -chm+bim+cgn-ain-bgo+aho -fhm+eim+fgn-din-ego+dho -ckm+blm+cjn-aln-bjo+ako -fkm+elm+fjn-dln-ejo+dko -ikm+hlm+ijn-gln-hjo+gko | 1 o3 : R-module, quotient of R i4 : C = res M 1 10 15 6 o4 = R <-- R <-- R <-- R <-- 0 0 1 2 3 4 o4 : ChainComplex i5 : D = eagonNorthcott f 1 10 15 6 o5 = R <-- R <-- R <-- R <-- 0 0 1 2 3 4 o5 : ChainComplex i6 : H = prune HH D o6 = 0 : cokernel | ikm-hlm-ijn+gln+hjo-gko fkm-elm-fjn+dln+ejo-dko ckm-blm-cjn+aln+bjo-ako fhm-eim-fgn+din+ego-dho chm-bim-cgn+ain+bgo-aho cem-bfm-cdn+afn+bdo-aeo fhj-eij-fgk+dik+egl-dhl chj-bij-cgk+aik+bgl-ahl cej-bfj-cdk+afk+bdl-ael ceg-bfg-cdh+afh+bdi-aei | 1 : 0 2 : 0 3 : 0 4 : 0 o6 : GradedModule i7 : assert( H_0 == M and H_1 == 0 and H_2 == 0 and H_3 == 0 ) i8 :