Changeset ffdeea5 in git
- Timestamp:
- Aug 22, 2008, 11:41:17 AM (15 years ago)
- Branches:
- (u'jengelh-datetime', 'ceac47cbc86fe4a15902392bdbb9bd2ae0ea02c6')(u'spielwiese', '0604212ebb110535022efecad887940825b97c3f')
- Children:
- 16643ec1a43713e7a67aeabfd52c3a248a77bd58
- Parents:
- c6c86ba35db6c94b41b12ad8e5eb5b1bc0552952
- File:
-
- 1 edited
Legend:
- Unmodified
- Added
- Removed
-
Singular/LIB/homolog.lib
rc6c86b rffdeea5 1 1 /////////////////////////////////////////////////////////////////////////////// 2 version="$Id: homolog.lib,v 1.2 4 2008-02-22 10:25:06Singular Exp $";2 version="$Id: homolog.lib,v 1.25 2008-08-22 09:41:17 Singular Exp $"; 3 3 category="Commutative Algebra"; 4 4 info=" … … 22 22 isLocallyFree(M,r); test if coker(M) is locally free of constant rank r 23 23 isReg(I,M); test if I is coker(M)-sequence, I ideal, M module 24 ker nel(A,M,N);ker(M'--A->N') M,N modules, A matrix24 ker(A,M,N); ker(M'--A->N') M,N modules, A matrix 25 25 kohom(A,k); Hom(R^k,A), A matrix over basering R 26 26 kontrahom(A,k); Hom(A,R^k), A matrix over basering R … … 1127 1127 ////////////////////////////////////////////////////////////////////////////// 1128 1128 1129 proc ker nel(matrix A,module M,module N)1130 "USAGE: ker nel(A,M,N);1129 proc ker (matrix A,module M,module N) 1130 "USAGE: ker(A,M,N); 1131 1131 COMPUTE: Let M and N be submodules of R^m and R^n, presenting M'=R^m/M, 1132 1132 N'=R^n/N (R=basering), and let A:R^m-->R^n be a matrix inducing a 1133 map A':M'-->N'. Then ker nel(A,M,N); computes a presentation K of1133 map A':M'-->N'. Then ker(A,M,N); computes a presentation K of 1134 1134 ker(A') as in the commutative diagram: 1135 1135 @example … … 1144 1144 @end example 1145 1145 RETURN: module K, a presentation of ker(A':coker(M)->coker(N)). 1146 EXAMPLE: example ker nel; shows examples.1146 EXAMPLE: example ker; shows examples. 1147 1147 " 1148 1148 { … … 1156 1156 module M=maxideal(1)*freemodule(2); 1157 1157 matrix A[2][3]=2x,0,x,y,z2,y; 1158 module K=ker nel(A,M,N);1158 module K=ker(A,M,N); 1159 1159 // dimension of kernel: 1160 1160 dim(std(K));
Note: See TracChangeset
for help on using the changeset viewer.