let A, B be Subset of (TOP-REAL 2); ( A c= B & LMP B in A & not A /\ (Vertical_Line (((W-bound A) + (E-bound A)) / 2)) is empty & proj2 .: (B /\ (Vertical_Line (((W-bound B) + (E-bound B)) / 2))) is bounded_below & (W-bound A) + (E-bound A) = (W-bound B) + (E-bound B) implies LMP A = LMP B )
assume that
A1:
A c= B
and
A2:
LMP B in A
and
A3:
not A /\ (Vertical_Line (((W-bound A) + (E-bound A)) / 2)) is empty
and
A4:
proj2 .: (B /\ (Vertical_Line (((W-bound B) + (E-bound B)) / 2))) is bounded_below
and
A5:
(W-bound A) + (E-bound A) = (W-bound B) + (E-bound B)
; LMP A = LMP B
set w = ((W-bound A) + (E-bound A)) / 2;
A6:
( (LMP A) `2 = lower_bound (proj2 .: (A /\ (Vertical_Line (((W-bound A) + (E-bound A)) / 2)))) & not proj2 .: (A /\ (Vertical_Line (((W-bound A) + (E-bound A)) / 2))) is empty )
by A3, Lm1, EUCLID:52, RELAT_1:119;
A7:
(LMP B) `1 = ((W-bound A) + (E-bound A)) / 2
by A5, EUCLID:52;
A8:
for s being Real st 0 < s holds
ex r being Real st
( r in proj2 .: (A /\ (Vertical_Line (((W-bound A) + (E-bound A)) / 2))) & r < ((LMP B) `2) + s )
A10:
A /\ (Vertical_Line (((W-bound A) + (E-bound A)) / 2)) c= B /\ (Vertical_Line (((W-bound A) + (E-bound A)) / 2))
by A1, XBOOLE_1:26;
then A11:
proj2 .: (A /\ (Vertical_Line (((W-bound A) + (E-bound A)) / 2))) c= proj2 .: (B /\ (Vertical_Line (((W-bound A) + (E-bound A)) / 2)))
by RELAT_1:123;
(LMP B) `2 = lower_bound (proj2 .: (B /\ (Vertical_Line (((W-bound A) + (E-bound A)) / 2))))
by A5, EUCLID:52;
then A12:
for r being Real st r in proj2 .: (A /\ (Vertical_Line (((W-bound A) + (E-bound A)) / 2))) holds
(LMP B) `2 <= r
by A4, A5, A11, SEQ_4:def 2;
proj2 .: (A /\ (Vertical_Line (((W-bound A) + (E-bound A)) / 2))) is bounded_below
by A4, A5, A10, RELAT_1:123, XXREAL_2:44;
then
( (LMP A) `1 = ((W-bound A) + (E-bound A)) / 2 & (LMP A) `2 = (LMP B) `2 )
by A6, A12, A8, EUCLID:52, SEQ_4:def 2;
hence
LMP A = LMP B
by A7, TOPREAL3:6; verum