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D.15.6.26 grrndmap2

Procedure from library gradedModules.lib (see gradedModules_lib).

Usage:
grrndmap2(D,S), graded objects S and D

Return:
graded object

Purpose:
construct a random 0-deg graded homomorphism between target of D and S.

Example:
 
LIB "gradedModules.lib";
ring r=32003,(x,y,z),dp;
module D=grobj(module([y,0,z],[x2+y2,z,0]),intvec(0,1,0));
grview(D);
==> Graded homomorphism: r + r(-1) + r <- r(-1) + r(-2), given by a matrix, w\
   ith degrees: 
==>      ..1 ..2 ....
==>      --- --- +...
==>   0 :  1   2 |..1
==>   1 :  -   1 |..2
==>   0 :  1   - |..3
==>      === ===     
==>        1   2     
module S=grobj(module([x,0,y],[xy,zy+x2,0]),intvec(0,0,0));
grview(S);
==> Graded homomorphism: r^3 <- r(-1) + r(-2), given by a matrix, with degree\
   s: 
==>      ..1 ..2 ....
==>      --- --- +...
==>   0 :  1   2 |..1
==>   0 :  -   2 |..2
==>   0 :  1   - |..3
==>      === ===     
==>        1   2     
def G=grrndmap2(D,S);
grview(G);
==> Graded homomorphism: r^3 <- r + r(-1) + r, given by a square matrix, with\
    degrees: 
==>     .1 .2 .3 ...
==>     -- -- -- +..
==>  0 : 0  1  0 |.1
==>  0 : 0  1  0 |.2
==>  0 : 0  1  0 |.3
==>     == == ==    
==>      0  1  0