let f be constant standard special_circular_sequence; LSeg ((S-max (L~ f)),(SE-corner (L~ f))) misses LSeg ((NW-corner (L~ f)),(N-min (L~ f)))
A1:
( (NW-corner (L~ f)) `2 = N-bound (L~ f) & (N-min (L~ f)) `2 = N-bound (L~ f) )
by EUCLID:52;
assume
LSeg ((S-max (L~ f)),(SE-corner (L~ f))) meets LSeg ((NW-corner (L~ f)),(N-min (L~ f)))
; contradiction
then
(LSeg ((S-max (L~ f)),(SE-corner (L~ f)))) /\ (LSeg ((NW-corner (L~ f)),(N-min (L~ f)))) <> {}
;
then consider x being object such that
A2:
x in (LSeg ((S-max (L~ f)),(SE-corner (L~ f)))) /\ (LSeg ((NW-corner (L~ f)),(N-min (L~ f))))
by XBOOLE_0:def 1;
reconsider p = x as Point of (TOP-REAL 2) by A2;
p in LSeg ((NW-corner (L~ f)),(N-min (L~ f)))
by A2, XBOOLE_0:def 4;
then
( N-bound (L~ f) <= p `2 & p `2 <= N-bound (L~ f) )
by A1, TOPREAL1:4;
then A3:
p `2 = N-bound (L~ f)
by XXREAL_0:1;
A4:
( (SE-corner (L~ f)) `2 = S-bound (L~ f) & (S-max (L~ f)) `2 = S-bound (L~ f) )
by EUCLID:52;
x in LSeg ((S-max (L~ f)),(SE-corner (L~ f)))
by A2, XBOOLE_0:def 4;
then
p `2 <= S-bound (L~ f)
by A4, TOPREAL1:4;
hence
contradiction
by A3, TOPREAL5:16; verum