theorem Th57: :: JGRAPH_6:57

for a, b, c, d being Real
for p1, p2 being Point of (TOP-REAL 2) st a < b & c < d & p1 in LSeg (|[b,c]|,|[b,d]|) & p2 in LSeg (|[b,c]|,|[b,d]|) holds
( LE p1,p2, rectangle (a,b,c,d) iff p1 `2 >= p2 `2 )