let p1, p2 be Point of (TOP-REAL 2); :: thesis: for b, c, d being real number st p1 `1 < b & p1 `1 = p2 `1 & c <= p1 `2 & p1 `2 < p2 `2 & p2 `2 <= d holds
LE p1,p2, rectangle (p1 `1 ),b,c,d
let b, c, d be real number ; :: thesis: ( p1 `1 < b & p1 `1 = p2 `1 & c <= p1 `2 & p1 `2 < p2 `2 & p2 `2 <= d implies LE p1,p2, rectangle (p1 `1 ),b,c,d )
set K = rectangle (p1 `1 ),b,c,d;
set a = p1 `1 ;
assume A1:
( p1 `1 < b & p1 `1 = p2 `1 & c <= p1 `2 & p1 `2 < p2 `2 & p2 `2 <= d )
; :: thesis: LE p1,p2, rectangle (p1 `1 ),b,c,d
then A2:
( c <= p1 `2 & p1 `2 < d )
by XXREAL_0:2;
then A3:
c < d
by XXREAL_0:2;
( c <= p2 `2 & p2 `2 <= d )
by A1, XXREAL_0:2;
then
( p1 in LSeg |[(p1 `1 ),c]|,|[(p1 `1 ),d]| & p2 in LSeg |[(p1 `1 ),c]|,|[(p1 `1 ),d]| )
by A1, A2, A3, JGRAPH_6:10;
hence
LE p1,p2, rectangle (p1 `1 ),b,c,d
by A1, A3, JGRAPH_6:65; :: thesis: verum