let C be Simple_closed_curve; for n being Nat st 0 < n holds
UMP (L~ (Cage (C,n))) = UMP (Upper_Arc (L~ (Cage (C,n))))
let n be Nat; ( 0 < n implies UMP (L~ (Cage (C,n))) = UMP (Upper_Arc (L~ (Cage (C,n)))) )
set f = Cage (C,n);
set w = ((E-bound C) + (W-bound C)) / 2;
A1:
Upper_Arc (L~ (Cage (C,n))) c= L~ (Cage (C,n))
by JORDAN6:61;
A2:
(W-bound C) + (E-bound C) = (W-bound (L~ (Cage (C,n)))) + (E-bound (L~ (Cage (C,n))))
by JORDAN1G:33;
A3:
E-bound (L~ (Cage (C,n))) = E-bound (Upper_Arc (L~ (Cage (C,n))))
by JORDAN21:18;
A4:
W-bound (L~ (Cage (C,n))) = W-bound (Upper_Arc (L~ (Cage (C,n))))
by JORDAN21:17;
assume A5:
0 < n
; UMP (L~ (Cage (C,n))) = UMP (Upper_Arc (L~ (Cage (C,n))))
then A6:
0 + 1 <= n
by NAT_1:13;
then A7:
(n -' 1) + 1 = n
by XREAL_1:235;
A8:
now UMP (L~ (Cage (C,n))) in Upper_Arc (L~ (Cage (C,n)))A9:
Center (Gauge (C,1)) <= len (Gauge (C,1))
by JORDAN1B:13;
A10:
Center (Gauge (C,n)) <= len (Gauge (C,n))
by JORDAN1B:13;
A11:
(Upper_Arc (L~ (Cage (C,n)))) \/ (Lower_Arc (L~ (Cage (C,n)))) = L~ (Cage (C,n))
by JORDAN6:def 9;
assume A12:
not
UMP (L~ (Cage (C,n))) in Upper_Arc (L~ (Cage (C,n)))
;
contradiction
UMP (L~ (Cage (C,n))) in L~ (Cage (C,n))
by JORDAN21:30;
then A13:
UMP (L~ (Cage (C,n))) in Lower_Arc (L~ (Cage (C,n)))
by A12, A11, XBOOLE_0:def 3;
A14:
len (Gauge (C,n)) = width (Gauge (C,n))
by JORDAN8:def 1;
A15:
1
<= Center (Gauge (C,n))
by JORDAN1B:11;
consider j being
Nat such that A16:
1
<= j
and A17:
j <= len (Gauge (C,n))
and A18:
UMP (L~ (Cage (C,n))) = (Gauge (C,n)) * (
(Center (Gauge (C,n))),
j)
by A5, Th19;
set a =
(Gauge (C,1)) * (
(Center (Gauge (C,1))),
(len (Gauge (C,1))));
set b =
(Gauge (C,n)) * (
(Center (Gauge (C,n))),
j);
set L =
LSeg (
((Gauge (C,1)) * ((Center (Gauge (C,1))),(len (Gauge (C,1))))),
((Gauge (C,n)) * ((Center (Gauge (C,n))),j)));
len (Gauge (C,1)) = width (Gauge (C,1))
by JORDAN8:def 1;
then
LSeg (
((Gauge (C,1)) * ((Center (Gauge (C,1))),(len (Gauge (C,1))))),
((Gauge (C,n)) * ((Center (Gauge (C,n))),j)))
meets Upper_Arc (L~ (Cage (C,n)))
by A7, A13, A16, A17, A18, A14, JORDAN19:5;
then consider x being
object such that A19:
x in LSeg (
((Gauge (C,1)) * ((Center (Gauge (C,1))),(len (Gauge (C,1))))),
((Gauge (C,n)) * ((Center (Gauge (C,n))),j)))
and A20:
x in Upper_Arc (L~ (Cage (C,n)))
by XBOOLE_0:3;
reconsider x =
x as
Point of
(TOP-REAL 2) by A19;
A21:
(Gauge (C,1)) * (
(Center (Gauge (C,1))),
(len (Gauge (C,1))))
in LSeg (
((Gauge (C,1)) * ((Center (Gauge (C,1))),(len (Gauge (C,1))))),
((Gauge (C,n)) * ((Center (Gauge (C,n))),j)))
by RLTOPSP1:68;
A22:
1
<= len (Gauge (C,1))
by Lm3;
then A23:
((Gauge (C,1)) * ((Center (Gauge (C,1))),(len (Gauge (C,1))))) `1 = ((E-bound C) + (W-bound C)) / 2
by JORDAN1A:38;
then A24:
((Gauge (C,n)) * ((Center (Gauge (C,n))),j)) `1 = ((E-bound C) + (W-bound C)) / 2
by A5, A16, A17, A22, JORDAN1A:36;
then
LSeg (
((Gauge (C,1)) * ((Center (Gauge (C,1))),(len (Gauge (C,1))))),
((Gauge (C,n)) * ((Center (Gauge (C,n))),j))) is
vertical
by A23, SPPOL_1:16;
then A25:
x `1 = ((E-bound C) + (W-bound C)) / 2
by A19, A23, A21, SPPOL_1:def 3;
then
x in Vertical_Line (((E-bound C) + (W-bound C)) / 2)
;
then A26:
x in (Upper_Arc (L~ (Cage (C,n)))) /\ (Vertical_Line (((E-bound C) + (W-bound C)) / 2))
by A20, XBOOLE_0:def 4;
then A27:
(UMP (Upper_Arc (L~ (Cage (C,n))))) `2 >= x `2
by A2, A4, A3, JORDAN21:28;
1
<= Center (Gauge (C,1))
by JORDAN1B:11;
then A28:
((Gauge (C,1)) * ((Center (Gauge (C,1))),(len (Gauge (C,1))))) `2 >= ((Gauge (C,n)) * ((Center (Gauge (C,n))),(len (Gauge (C,n))))) `2
by A6, A15, A10, A9, JORDAN1A:40;
len (Gauge (C,n)) = width (Gauge (C,n))
by JORDAN8:def 1;
then
((Gauge (C,n)) * ((Center (Gauge (C,n))),(len (Gauge (C,n))))) `2 >= ((Gauge (C,n)) * ((Center (Gauge (C,n))),j)) `2
by A16, A17, A15, A10, SPRECT_3:12;
then
((Gauge (C,1)) * ((Center (Gauge (C,1))),(len (Gauge (C,1))))) `2 >= ((Gauge (C,n)) * ((Center (Gauge (C,n))),j)) `2
by A28, XXREAL_0:2;
then A29:
x `2 >= ((Gauge (C,n)) * ((Center (Gauge (C,n))),j)) `2
by A19, TOPREAL1:4;
(UMP (L~ (Cage (C,n)))) `2 >= (UMP (Upper_Arc (L~ (Cage (C,n))))) `2
by A1, A2, A4, A3, A26, JORDAN21:13, JORDAN21:43;
then
((Gauge (C,n)) * ((Center (Gauge (C,n))),j)) `2 >= x `2
by A18, A27, XXREAL_0:2;
then
((Gauge (C,n)) * ((Center (Gauge (C,n))),j)) `2 = x `2
by A29, XXREAL_0:1;
hence
contradiction
by A12, A18, A20, A24, A25, TOPREAL3:6;
verum end;
proj2 .: ((L~ (Cage (C,n))) /\ (Vertical_Line (((E-bound C) + (W-bound C)) / 2))) is bounded_above
by A2, JORDAN21:13;
hence
UMP (L~ (Cage (C,n))) = UMP (Upper_Arc (L~ (Cage (C,n))))
by A1, A2, A4, A3, A8, JORDAN21:21, JORDAN21:45; verum