:: deftheorem Def04 defines BinOpLineHomography3 BKMODEL3:def 5 :
for b₁ being BinOp of EnsLineHomography3 holds
( b₁ = BinOpLineHomography3 iff for h1, h2 being Element of EnsLineHomography3 holds b₁ . (h1,h2) = h1 (*) h2 );