theorem Th26: :: MATRIX_3:26
for D, I, J being non empty set
for F, G being BinOp of D
for f being Function of I,D
for g being Function of J,D
for X being Element of Fin I
for Y being Element of Fin J st F is having_a_unity & F is commutative & F is associative & F is having_an_inverseOp & G is_distributive_wrt F holds
F $$ ([:X,Y:],(G * (f,g))) = F $$ (X,(G [:] (f,(F $$ (Y,g)))))