:: deftheorem Rescher defines Rescher_implication FUZIMPL1:def 20 :
for b₁ being BinOp of [.0,1.] holds
( b₁ = Rescher_implication iff for x, y being Element of [.0,1.] holds
( ( x <= y implies b₁ . (x,y) = 1 ) & ( x > y implies b₁ . (x,y) = 0 ) ) );