let z be non constant standard clockwise_oriented special_circular_sequence; :: thesis: ( z /. 1 = N-min (L~ z) & N-max (L~ z) <> E-max (L~ z) implies (N-max (L~ z)) .. z < (E-max (L~ z)) .. z )
set i1 = (N-max (L~ z)) .. z;
set i2 = (E-max (L~ z)) .. z;
set j = (S-max (L~ z)) .. z;
assume that
A1: z /. 1 = N-min (L~ z) and
A2: N-max (L~ z) <> E-max (L~ z) and
A3: (N-max (L~ z)) .. z >= (E-max (L~ z)) .. z ; :: thesis: contradiction
A4: E-max (L~ z) in rng z by Th50;
A5: S-max (L~ z) in rng z by Th46;
A6: N-max (L~ z) in rng z by Th44;
A7: 1 in dom z by FINSEQ_5:6;
A8: (N-max (L~ z)) .. z in dom z by A6, FINSEQ_4:30;
then A9: ( 1 <= (N-max (L~ z)) .. z & (N-max (L~ z)) .. z <= len z ) by FINSEQ_3:27;
A10: (S-max (L~ z)) .. z in dom z by A5, FINSEQ_4:30;
then A11: ( 1 <= (S-max (L~ z)) .. z & (S-max (L~ z)) .. z <= len z ) by FINSEQ_3:27;
A12: z /. ((S-max (L~ z)) .. z) = z . ((S-max (L~ z)) .. z) by A10, PARTFUN1:def 8
.= S-max (L~ z) by A5, FINSEQ_4:29 ;
A13: (E-max (L~ z)) .. z in dom z by A4, FINSEQ_4:30;
then A14: ( 1 <= (E-max (L~ z)) .. z & (E-max (L~ z)) .. z <= len z ) by FINSEQ_3:27;
A15: z /. ((N-max (L~ z)) .. z) = z . ((N-max (L~ z)) .. z) by A8, PARTFUN1:def 8
.= N-max (L~ z) by A6, FINSEQ_4:29 ;
A16: (S-max (L~ z)) .. z > (N-max (L~ z)) .. z by A1, Lm5;
( (N-min (L~ z)) `2 = N-bound (L~ z) & (S-max (L~ z)) `2 = S-bound (L~ z) ) by EUCLID:56;
then A17: N-min (L~ z) <> S-max (L~ z) by TOPREAL5:22;
z /. (len z) = z /. 1 by FINSEQ_6:def 1;
then A18: (S-max (L~ z)) .. z < len z by A1, A11, A12, A17, XXREAL_0:1;
then reconsider h = mid z,((S-max (L~ z)) .. z),((N-max (L~ z)) .. z) as S-Sequence_in_R2 by A9, A16, Th41;
A19: h is_in_the_area_of z by A8, A10, Th25, Th26;
h /. 1 = S-max (L~ z) by A8, A10, A12, Th12;
then A20: (h /. 1) `2 = S-bound (L~ z) by EUCLID:56;
h /. (len h) = z /. ((N-max (L~ z)) .. z) by A8, A10, Th13;
then (h /. (len h)) `2 = N-bound (L~ z) by A15, EUCLID:56;
then A21: h is_a_v.c._for z by A19, A20, Def3;
(N-min (L~ z)) .. z = 1 by A1, FINSEQ_6:47;
then A22: 1 < (E-max (L~ z)) .. z by A1, Lm4;
z /. ((E-max (L~ z)) .. z) = z . ((E-max (L~ z)) .. z) by A13, PARTFUN1:def 8
.= E-max (L~ z) by A4, FINSEQ_4:29 ;
then A23: (N-max (L~ z)) .. z > (E-max (L~ z)) .. z by A2, A3, A15, XXREAL_0:1;
then (E-max (L~ z)) .. z < len z by A9, XXREAL_0:2;
then reconsider M = mid z,1,((E-max (L~ z)) .. z) as S-Sequence_in_R2 by A22, Th42;
A24: ( len M >= 2 & len h >= 2 ) by TOPREAL1:def 10;
A25: L~ M misses L~ h by A16, A18, A22, A23, Th52;
A26: M /. (len M) = z /. ((E-max (L~ z)) .. z) by A7, A13, Th13
.= E-max (L~ z) by A4, FINSEQ_5:41 ;
per cases ( NW-corner (L~ z) = N-min (L~ z) or NW-corner (L~ z) <> N-min (L~ z) ) ;
suppose A27: NW-corner (L~ z) = N-min (L~ z) ; :: thesis: contradiction
end;
suppose NW-corner (L~ z) <> N-min (L~ z) ; :: thesis: contradiction
end;
end;