theorem Th27: :: FILTER_1:27

for D1, D2 being non empty set
for f1, g1 being BinOp of D1
for f2, g2 being BinOp of D2 holds
( ( f1 is_left_distributive_wrt g1 & f2 is_left_distributive_wrt g2 ) iff |:f1,f2:| is_left_distributive_wrt |:g1,g2:| )