-- -*- M2-comint -*- hash: 11558865560507179109

i1 : needsPackage "OldChainComplexes"

o1 = OldChainComplexes

o1 : Package

i2 : R = QQ[a..z]

o2 = R

o2 : PolynomialRing

i3 : f = genericMatrix(R,3,5)

o3 = | a d g j m |
     | b e h k n |
     | c f i l o |

             3      5
o3 : Matrix R  <-- R

i4 : M = coker gens minors_3 f

o4 = 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
o4 : R-module, quotient of R

i5 : C = res M

      1      10      15      6
o5 = R  <-- R   <-- R   <-- R  <-- 0
                                    
     0      1       2       3      4

o5 : ChainComplex

i6 : D = eagonNorthcott f

      1      10      15      6
o6 = R  <-- R   <-- R   <-- R  <-- 0
                                    
     0      1       2       3      4

o6 : ChainComplex

i7 : H = prune HH D

o7 = 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                                                         

o7 : GradedModule

i8 : assert( H_0 == M and H_1 == 0 and H_2 == 0 and H_3 == 0 )

i9 : 
