  Key
    schurModulesMap
    (schurModulesMap, Module, Module, Function)
  Headline
    creates a map between two Schur modules via the specified function.
  Usage
    schurModulesMap(N,M,F)
  Inputs
    N:Module
	Schur module
    M:Module
	Schur module
    F:Function 
        The function should specify, for every SST in the basis of M, 
	a linear combination of tableaux of the shape specified by N.
        The output of F should be a sequence of pairs (c,T) where c is a coefficient 
	in ring(N) and T a tableau (not necessarily semistandard). 
  Outputs
    G:Matrix
	A map between M and N.
  Description
    Text
      Constructs the map between M and N specified by the function F.
    Example 
      n = 4;      --j-th differential of the Koszul Complex on the variables of R
      j = 2;
      mu1=apply(j,j->1)
      mu2=apply(j+1,j->1)
      R = QQ[x_1..x_n];
      M=schurModule(mu1,R^n);
      N=schurModule(mu2,R^n);
      F = T -> apply(numgens R, j -> (R_j, augmentFilling(T,0,j)))
      schurModulesMap(N,M,F)
  Caveat
    The function F should output lists of pairs where the second component is a filling of the partition corresponding to N.
  SeeAlso
    schur
