# diff'(Matrix,Matrix) -- differentiate a matrix by a matrix, the dual notion

## Synopsis

• Function: diff'
• Usage:
h = diff'(m,n)
• Inputs:
• m, , a map m : F <--- P between free modules of ranks f and p.
• n, , a map n : G <--- Q between free modules of ranks g and q.
• Outputs:
• h, , a matrix with the shape h : F ** dual G <--- P ** dual Q, whose entry in the slot hg*i+j,q*k+l is the result of differentiating nj,l, by mi,k