prune Matrix -- minimize generators and relations

prune Matrix -- minimize generators and relations

Synopsis:

Usage: h = prune f

Function: prune -- minimize generators and relations

Input:

f, an instance of class Matrix.

Output:

h, an instance of class Matrix: the map corresponding to f obtained by pruning its source and target

See also:

presentation -- presentation of a module or ring

trim -- simplify the presentation

Code:

     -- ../../../Macaulay2/m2/modules2.m2:440-445
     prune(Matrix) := Matrix => (m) -> (
          M := source m;
          if not M.?pruningMap then m = m * (prune M).pruningMap;
          N := target m;
          if not N.?pruningMap then m = (prune N).pruningMap^-1 * m;
          m)