let z be non constant standard clockwise_oriented special_circular_sequence; :: thesis: ( z /. 1 = N-min (L~ z) & E-min (L~ z) <> S-max (L~ z) implies (E-min (L~ z)) .. z < (S-max (L~ z)) .. z )
set i1 = (E-min (L~ z)) .. z;
set i2 = (S-max (L~ z)) .. z;
assume that
A1: z /. 1 = N-min (L~ z) and
A2: E-min (L~ z) <> S-max (L~ z) and
A3: (E-min (L~ z)) .. z >= (S-max (L~ z)) .. z ; :: thesis: contradiction
A4: E-min (L~ z) in rng z by Th49;
A5: S-max (L~ z) in rng z by Th46;
A6: (E-min (L~ z)) .. z in dom z by A4, FINSEQ_4:30;
then A7: ( 1 <= (E-min (L~ z)) .. z & (E-min (L~ z)) .. z <= len z ) by FINSEQ_3:27;
A8: (S-max (L~ z)) .. z in dom z by A5, FINSEQ_4:30;
then A9: ( 1 <= (S-max (L~ z)) .. z & (S-max (L~ z)) .. z <= len z ) by FINSEQ_3:27;
A10: z /. ((S-max (L~ z)) .. z) = z . ((S-max (L~ z)) .. z) by A8, PARTFUN1:def 8
.= S-max (L~ z) by A5, FINSEQ_4:29 ;
A11: z /. (len z) = N-min (L~ z) by A1, FINSEQ_6:def 1;
A12: z /. ((E-min (L~ z)) .. z) = z . ((E-min (L~ z)) .. z) by A6, PARTFUN1:def 8
.= E-min (L~ z) by A4, FINSEQ_4:29 ;
then A13: (E-min (L~ z)) .. z > (S-max (L~ z)) .. z by A2, A3, A10, XXREAL_0:1;
then A14: (E-min (L~ z)) .. z > 1 by A9, XXREAL_0:2;
A15: len z in dom z by FINSEQ_5:6;
A16: z /. 1 = z /. (len z) by FINSEQ_6:def 1;
A17: 2 <= len z by REALSET1:13;
then A18: 2 in dom z by FINSEQ_3:27;
z /. 2 in N-most (L~ z) by A1, Th34;
then A19: (z /. 2) `2 = (N-min (L~ z)) `2 by PSCOMP_1:98
.= N-bound (L~ z) by EUCLID:56 ;
A20: (z /. 1) `2 = N-bound (L~ z) by A1, EUCLID:56;
A21: (S-max (L~ z)) .. z <> 0 by A8, FINSEQ_3:27;
A22: (z /. ((S-max (L~ z)) .. z)) `2 = S-bound (L~ z) by A10, EUCLID:56;
S-bound (L~ z) < N-bound (L~ z) by TOPREAL5:22;
then A23: (S-max (L~ z)) .. z > 2 by A19, A20, A21, A22, NAT_1:27;
then reconsider h = mid z,((S-max (L~ z)) .. z),2 as S-Sequence_in_R2 by A9, Th41;
A24: len h >= 2 by TOPREAL1:def 10;
A25: h is_in_the_area_of z by A8, A18, Th25, Th26;
h /. 1 = S-max (L~ z) by A8, A10, A18, Th12;
then A26: (h /. 1) `2 = S-bound (L~ z) by EUCLID:56;
h /. (len h) = z /. 2 by A8, A18, Th13;
then A27: h is_a_v.c._for z by A19, A25, A26, Def3;
N-max (L~ z) in L~ z by SPRECT_1:13;
then (N-max (L~ z)) `1 <= E-bound (L~ z) by PSCOMP_1:71;
then (N-min (L~ z)) `1 < E-bound (L~ z) by Th55, XXREAL_0:2;
then (N-min (L~ z)) `1 < (E-min (L~ z)) `1 by EUCLID:56;
then A28: (E-min (L~ z)) .. z < len z by A7, A11, A12, XXREAL_0:1;
then reconsider M = mid z,(len z),((E-min (L~ z)) .. z) as S-Sequence_in_R2 by A14, Th41;
A29: L~ M misses L~ h by A7, A13, A23, Th53;
A30: M /. (len M) = z /. ((E-min (L~ z)) .. z) by A6, A15, Th13
.= E-min (L~ z) by A4, FINSEQ_5:41 ;
A31: len M = ((len z) -' ((E-min (L~ z)) .. z)) + 1 by A7, JORDAN4:21;
((E-min (L~ z)) .. z) + 1 <= len z by A28, NAT_1:13;
then (len z) - ((E-min (L~ z)) .. z) >= 1 by XREAL_1:21;
then (len z) -' ((E-min (L~ z)) .. z) >= 1 by NAT_D:39;
then A32: ((len z) -' ((E-min (L~ z)) .. z)) + 1 >= 1 + 1 by XREAL_1:8;
A33: M /. 1 = z /. 1 by A6, A15, A16, Th12;
per cases ( NW-corner (L~ z) = N-min (L~ z) or NW-corner (L~ z) <> N-min (L~ z) ) ;
suppose A34: NW-corner (L~ z) = N-min (L~ z) ; :: thesis: contradiction
end;
suppose NW-corner (L~ z) <> N-min (L~ z) ; :: thesis: contradiction
end;
end;