set p2X = proj2 | X;
set c = the carrier of ((TOP-REAL 2) | X);
A19:
( (SW-corner X) `1 = W-bound X & (SE-corner X) `1 = E-bound X )
by EUCLID:56;
(proj2 | X) .: the carrier of ((TOP-REAL 2) | X) is with_min
by Def15;
then
inf ((proj2 | X) .: the carrier of ((TOP-REAL 2) | X)) in (proj2 | X) .: the carrier of ((TOP-REAL 2) | X)
by Def4;
then consider p being set such that
A20:
p in the carrier of ((TOP-REAL 2) | X)
and
p in the carrier of ((TOP-REAL 2) | X)
and
A21:
inf ((proj2 | X) .: the carrier of ((TOP-REAL 2) | X)) = (proj2 | X) . p
by FUNCT_2:115;
A22:
the carrier of ((TOP-REAL 2) | X) = X
by PRE_TOPC:29;
then reconsider p = p as Point of (TOP-REAL 2) by A20;
A23:
p `1 <= E-bound X
by A22, A20, Lm9;
A24:
( (SW-corner X) `2 = S-bound X & (SE-corner X) `2 = S-bound X )
by EUCLID:56;
( (proj2 | X) . p = p `2 & W-bound X <= p `1 )
by A22, A20, Lm9, Th70;
then
p in LSeg (SW-corner X),(SE-corner X)
by A19, A24, A21, A23, GOBOARD7:9;
hence
( not S-most X is empty & S-most X is compact )
by A22, A20, Th64, XBOOLE_0:def 4; verum