let f be non constant standard special_circular_sequence; LSeg ((((1 / 2) * (((GoB f) * (1,((width (GoB f)) -' 1))) + ((GoB f) * (1,(width (GoB f)))))) - |[1,0]|),(((GoB f) * (1,(width (GoB f)))) + |[(- 1),1]|)) misses L~ f
A1:
1 <= len (GoB f)
by GOBOARD7:32;
now for p being Point of (TOP-REAL 2) st p in LSeg ((((1 / 2) * (((GoB f) * (1,((width (GoB f)) -' 1))) + ((GoB f) * (1,(width (GoB f)))))) - |[1,0]|),(((GoB f) * (1,(width (GoB f)))) + |[(- 1),1]|)) holds
p `1 < ((GoB f) * (1,1)) `1 A2:
1
< width (GoB f)
by GOBOARD7:33;
then A3:
((width (GoB f)) -' 1) + 1
= width (GoB f)
by XREAL_1:235;
then A4:
(width (GoB f)) -' 1
<= width (GoB f)
by NAT_1:11;
A5:
((GoB f) * (1,(width (GoB f)))) `1 = ((GoB f) * (1,1)) `1
by A1, A2, GOBOARD5:2;
then (((GoB f) * (1,(width (GoB f)))) + |[(- 1),1]|) `1 =
(((GoB f) * (1,1)) `1) + (|[(- 1),1]| `1)
by TOPREAL3:2
.=
(((GoB f) * (1,1)) `1) + (- 1)
by EUCLID:52
.=
(((GoB f) * (1,1)) `1) - 1
;
then A6:
((GoB f) * (1,(width (GoB f)))) + |[(- 1),1]| = |[((((GoB f) * (1,1)) `1) - 1),((((GoB f) * (1,(width (GoB f)))) + |[(- 1),1]|) `2)]|
by EUCLID:53;
1
<= (width (GoB f)) -' 1
by A2, A3, NAT_1:13;
then A7:
((GoB f) * (1,((width (GoB f)) -' 1))) `1 = ((GoB f) * (1,1)) `1
by A1, A4, GOBOARD5:2;
(((1 / 2) * (((GoB f) * (1,((width (GoB f)) -' 1))) + ((GoB f) * (1,(width (GoB f)))))) - |[1,0]|) `1 =
(((1 / 2) * (((GoB f) * (1,((width (GoB f)) -' 1))) + ((GoB f) * (1,(width (GoB f)))))) `1) - (|[1,0]| `1)
by TOPREAL3:3
.=
((1 / 2) * ((((GoB f) * (1,((width (GoB f)) -' 1))) + ((GoB f) * (1,(width (GoB f))))) `1)) - (|[1,0]| `1)
by TOPREAL3:4
.=
((1 / 2) * ((((GoB f) * (1,1)) `1) + (((GoB f) * (1,1)) `1))) - (|[1,0]| `1)
by A7, A5, TOPREAL3:2
.=
(1 * (((GoB f) * (1,1)) `1)) - 1
by EUCLID:52
;
then A8:
((1 / 2) * (((GoB f) * (1,((width (GoB f)) -' 1))) + ((GoB f) * (1,(width (GoB f)))))) - |[1,0]| = |[((((GoB f) * (1,1)) `1) - 1),((((1 / 2) * (((GoB f) * (1,((width (GoB f)) -' 1))) + ((GoB f) * (1,(width (GoB f)))))) - |[1,0]|) `2)]|
by EUCLID:53;
let p be
Point of
(TOP-REAL 2);
( p in LSeg ((((1 / 2) * (((GoB f) * (1,((width (GoB f)) -' 1))) + ((GoB f) * (1,(width (GoB f)))))) - |[1,0]|),(((GoB f) * (1,(width (GoB f)))) + |[(- 1),1]|)) implies p `1 < ((GoB f) * (1,1)) `1 )assume
p in LSeg (
(((1 / 2) * (((GoB f) * (1,((width (GoB f)) -' 1))) + ((GoB f) * (1,(width (GoB f)))))) - |[1,0]|),
(((GoB f) * (1,(width (GoB f)))) + |[(- 1),1]|))
;
p `1 < ((GoB f) * (1,1)) `1 then
p `1 = (((GoB f) * (1,1)) `1) - 1
by A8, A6, TOPREAL3:11;
hence
p `1 < ((GoB f) * (1,1)) `1
by XREAL_1:44;
verum end;
hence
LSeg ((((1 / 2) * (((GoB f) * (1,((width (GoB f)) -' 1))) + ((GoB f) * (1,(width (GoB f)))))) - |[1,0]|),(((GoB f) * (1,(width (GoB f)))) + |[(- 1),1]|)) misses L~ f
by Th21; verum