theorem Th51: :: JGRAPH_7:51

for A, B, C, D being Real
for h being Function of (TOP-REAL 2),(TOP-REAL 2) st A > 0 & C > 0 & h = AffineMap (A,B,C,D) holds
( h is being_homeomorphism & ( for p1, p2 being Point of (TOP-REAL 2) st p1 `2 < p2 `2 holds
(h . p1) `2 < (h . p2) `2 ) )