reconsider h2 = proj2 as Function of (TOP-REAL 2),R^1 by TOPMETR:17;
let P be non empty compact Subset of (TOP-REAL 2); :: thesis: ( P = { q where q is Point of (TOP-REAL 2) : |.q.| = 1 } implies Upper_Arc P = { p where p is Point of (TOP-REAL 2) : ( p in P & p `2 >= 0 ) } )
set P4 = Lower_Arc P;
set P1 = Upper_Arc P;
set P2 = Lower_Arc P;
set Q = Vertical_Line 0;
set p8 = First_Point ((Upper_Arc P),(W-min P),(E-max P),(Vertical_Line 0));
set pj = Last_Point ((Lower_Arc P),(E-max P),(W-min P),(Vertical_Line 0));
A1: LSeg (|[0,(- 1)]|,|[0,1]|) c= Vertical_Line 0
proof
let x be object ; :: according to TARSKI:def 3 :: thesis: ( not x in LSeg (|[0,(- 1)]|,|[0,1]|) or x in Vertical_Line 0 )
assume x in LSeg (|[0,(- 1)]|,|[0,1]|) ; :: thesis: x in Vertical_Line 0
then consider l being Real such that
A2: x = ((1 - l) * |[0,(- 1)]|) + (l * |[0,1]|) and
0 <= l and
l <= 1 ;
(((1 - l) * |[0,(- 1)]|) + (l * |[0,1]|)) `1 = (((1 - l) * |[0,(- 1)]|) `1) + ((l * |[0,1]|) `1) by TOPREAL3:2
.= ((1 - l) * (|[0,(- 1)]| `1)) + ((l * |[0,1]|) `1) by TOPREAL3:4
.= ((1 - l) * (|[0,(- 1)]| `1)) + (l * (|[0,1]| `1)) by TOPREAL3:4
.= ((1 - l) * 0) + (l * (|[0,1]| `1)) by EUCLID:52
.= ((1 - l) * 0) + (l * 0) by EUCLID:52
.= 0 ;
hence x in Vertical_Line 0 by A2; :: thesis: verum
end;
reconsider R = Upper_Arc P as non empty Subset of (TOP-REAL 2) ;
assume A3: P = { q where q is Point of (TOP-REAL 2) : |.q.| = 1 } ; :: thesis: Upper_Arc P = { p where p is Point of (TOP-REAL 2) : ( p in P & p `2 >= 0 ) }
then A4: P is being_simple_closed_curve by JGRAPH_3:26;
then A5: Upper_Arc P is_an_arc_of W-min P, E-max P by JORDAN6:def 8;
then consider f being Function of I[01],((TOP-REAL 2) | R) such that
A6: f is being_homeomorphism and
A7: f . 0 = W-min P and
A8: f . 1 = E-max P by TOPREAL1:def 1;
A9: ( dom f = the carrier of I[01] & dom h2 = the carrier of (TOP-REAL 2) ) by FUNCT_2:def 1;
A10: ex P2 being non empty Subset of (TOP-REAL 2) st
( P2 is_an_arc_of E-max P, W-min P & (Upper_Arc P) /\ P2 = {(W-min P),(E-max P)} & (Upper_Arc P) \/ P2 = P & (First_Point ((Upper_Arc P),(W-min P),(E-max P),(Vertical_Line (((W-bound P) + (E-bound P)) / 2)))) `2 > (Last_Point (P2,(E-max P),(W-min P),(Vertical_Line (((W-bound P) + (E-bound P)) / 2)))) `2 ) by A4, JORDAN6:def 8;
then A11: Upper_Arc P c= P by XBOOLE_1:7;
A12: rng f = [#] ((TOP-REAL 2) | R) by A6, TOPS_2:def 5
.= R by PRE_TOPC:def 5 ;
A13: ( S-bound P = - 1 & N-bound P = 1 ) by A3, Th28;
A14: Vertical_Line 0 is closed by JORDAN6:30;
A15: for p being Point of (TOP-REAL 2) holds h2 . p = proj2 . p ;
A16: ( W-bound P = - 1 & E-bound P = 1 ) by A3, Th28;
then A17: Upper_Arc P meets Vertical_Line 0 by A4, A13, A1, JORDAN6:69, XBOOLE_1:64;
A18: Lower_Arc P meets Vertical_Line 0 by A4, A16, A13, A1, JORDAN6:70, XBOOLE_1:64;
A19: (First_Point ((Upper_Arc P),(W-min P),(E-max P),(Vertical_Line (((W-bound P) + (E-bound P)) / 2)))) `2 > (Last_Point ((Lower_Arc P),(E-max P),(W-min P),(Vertical_Line (((W-bound P) + (E-bound P)) / 2)))) `2 by A4, JORDAN6:def 9;
Upper_Arc P is closed by A5, JORDAN6:11;
then (Upper_Arc P) /\ (Vertical_Line 0) is closed by A14, TOPS_1:8;
then A20: First_Point ((Upper_Arc P),(W-min P),(E-max P),(Vertical_Line 0)) in (Upper_Arc P) /\ (Vertical_Line 0) by A5, A17, JORDAN5C:def 1;
then First_Point ((Upper_Arc P),(W-min P),(E-max P),(Vertical_Line 0)) in Upper_Arc P by XBOOLE_0:def 4;
then consider x8 being object such that
A21: x8 in dom f and
A22: First_Point ((Upper_Arc P),(W-min P),(E-max P),(Vertical_Line 0)) = f . x8 by A12, FUNCT_1:def 3;
dom f = [.0,1.] by BORSUK_1:40, FUNCT_2:def 1;
then x8 in { r where r is Real : ( 0 <= r & r <= 1 ) } by A21, RCOMP_1:def 1;
then consider r8 being Real such that
A23: x8 = r8 and
A24: 0 <= r8 and
A25: r8 <= 1 ;
A26: Vertical_Line 0 is closed by JORDAN6:30;
(Upper_Arc P) /\ (Vertical_Line 0) c= {|[0,(- 1)]|,|[0,1]|}
proof
let x be object ; :: according to TARSKI:def 3 :: thesis: ( not x in (Upper_Arc P) /\ (Vertical_Line 0) or x in {|[0,(- 1)]|,|[0,1]|} )
assume A27: x in (Upper_Arc P) /\ (Vertical_Line 0) ; :: thesis: x in {|[0,(- 1)]|,|[0,1]|}
then x in Upper_Arc P by XBOOLE_0:def 4;
then x in P by A10, XBOOLE_0:def 3;
then consider q being Point of (TOP-REAL 2) such that
A28: q = x and
A29: |.q.| = 1 by A3;
x in Vertical_Line 0 by A27, XBOOLE_0:def 4;
then A30: ex p being Point of (TOP-REAL 2) st
( p = x & p `1 = 0 ) ;
then (0 ^2) + ((q `2) ^2) = 1 ^2 by A28, A29, JGRAPH_3:1;
then ( q `2 = 1 or q `2 = - 1 ) by SQUARE_1:41;
then ( x = |[0,(- 1)]| or x = |[0,1]| ) by A30, A28, EUCLID:53;
hence x in {|[0,(- 1)]|,|[0,1]|} by TARSKI:def 2; :: thesis: verum
end;
then ( First_Point ((Upper_Arc P),(W-min P),(E-max P),(Vertical_Line 0)) = |[0,(- 1)]| or First_Point ((Upper_Arc P),(W-min P),(E-max P),(Vertical_Line 0)) = |[0,1]| ) by A20, TARSKI:def 2;
then A31: ( (First_Point ((Upper_Arc P),(W-min P),(E-max P),(Vertical_Line 0))) `2 = - 1 or (First_Point ((Upper_Arc P),(W-min P),(E-max P),(Vertical_Line 0))) `2 = 1 ) by EUCLID:52;
A32: now :: thesis: not r8 = 0 end;
A33: rng (h2 * f) c= the carrier of R^1 ;
A34: the carrier of ((TOP-REAL 2) | R) = R by PRE_TOPC:8;
then rng f c= the carrier of (TOP-REAL 2) by XBOOLE_1:1;
then dom (h2 * f) = the carrier of I[01] by A9, RELAT_1:27;
then reconsider g0 = h2 * f as Function of I[01],R^1 by A33, FUNCT_2:2;
A35: f is one-to-one by A6, TOPS_2:def 5;
A36: f is continuous by A6, TOPS_2:def 5;
A37: ( ex p being Point of (TOP-REAL 2) ex t being Real st
( 0 < t & t < 1 & f . t = p & p `2 > 0 ) implies for q being Point of (TOP-REAL 2) st q in Upper_Arc P holds
q `2 >= 0 )
proof
given p being Point of (TOP-REAL 2), t being Real such that A38: 0 < t and
A39: t < 1 and
A40: f . t = p and
A41: p `2 > 0 ; :: thesis: for q being Point of (TOP-REAL 2) st q in Upper_Arc P holds
q `2 >= 0

now :: thesis: for q being Point of (TOP-REAL 2) holds
( not q in Upper_Arc P or not q `2 < 0 )
assume ex q being Point of (TOP-REAL 2) st
( q in Upper_Arc P & q `2 < 0 ) ; :: thesis: contradiction
then consider q being Point of (TOP-REAL 2) such that
A42: q in Upper_Arc P and
A43: q `2 < 0 ;
rng f = [#] ((TOP-REAL 2) | R) by A6, TOPS_2:def 5
.= R by PRE_TOPC:def 5 ;
then consider x being object such that
A44: x in dom f and
A45: q = f . x by A42, FUNCT_1:def 3;
A46: dom f = [.0,1.] by BORSUK_1:40, FUNCT_2:def 1;
then A47: x in { r where r is Real : ( 0 <= r & r <= 1 ) } by A44, RCOMP_1:def 1;
t in { v where v is Real : ( 0 <= v & v <= 1 ) } by A38, A39;
then A48: t in [.0,1.] by RCOMP_1:def 1;
then A49: (h2 * f) . t = h2 . p by A40, A46, FUNCT_1:13
.= p `2 by PSCOMP_1:def 6 ;
consider r being Real such that
A50: x = r and
A51: 0 <= r and
A52: r <= 1 by A47;
A53: (h2 * f) . r = h2 . q by A44, A45, A50, FUNCT_1:13
.= q `2 by PSCOMP_1:def 6 ;
now :: thesis: ( ( r < t & contradiction ) or ( t < r & contradiction ) or ( t = r & contradiction ) )
per cases ( r < t or t < r or t = r ) by XXREAL_0:1;
case A54: r < t ; :: thesis: contradiction
then reconsider B = [.r,t.] as non empty Subset of I[01] by A44, A50, A48, BORSUK_1:40, XXREAL_1:1, XXREAL_2:def 12;
reconsider B0 = B as Subset of I[01] ;
reconsider g = g0 | B0 as Function of (I[01] | B0),R^1 by PRE_TOPC:9;
A55: (q `2) * (p `2) < 0 by A41, A43, XREAL_1:132;
t in { r4 where r4 is Real : ( r <= r4 & r4 <= t ) } by A54;
then t in B by RCOMP_1:def 1;
then A56: p `2 = g . t by A49, FUNCT_1:49;
r in { r4 where r4 is Real : ( r <= r4 & r4 <= t ) } by A54;
then r in B by RCOMP_1:def 1;
then A57: q `2 = g . r by A53, FUNCT_1:49;
g0 is continuous by A36, A15, Th7, Th32;
then A58: g is continuous by TOPMETR:7;
Closed-Interval-TSpace (r,t) = I[01] | B by A39, A51, A54, TOPMETR:20, TOPMETR:23;
then consider r1 being Real such that
A59: g . r1 = 0 and
A60: r < r1 and
A61: r1 < t by A54, A58, A55, A57, A56, TOPREAL5:8;
r1 in { r4 where r4 is Real : ( r <= r4 & r4 <= t ) } by A60, A61;
then A62: r1 in B by RCOMP_1:def 1;
r1 < 1 by A39, A61, XXREAL_0:2;
then r1 in { r2 where r2 is Real : ( 0 <= r2 & r2 <= 1 ) } by A51, A60;
then A63: r1 in dom f by A46, RCOMP_1:def 1;
then f . r1 in rng f by FUNCT_1:def 3;
then f . r1 in R by A34;
then f . r1 in P by A11;
then consider q3 being Point of (TOP-REAL 2) such that
A64: q3 = f . r1 and
A65: |.q3.| = 1 by A3;
A66: q3 `2 = h2 . (f . r1) by A64, PSCOMP_1:def 6
.= g0 . r1 by A63, FUNCT_1:13
.= 0 by A59, A62, FUNCT_1:49 ;
then A67: 1 ^2 = ((q3 `1) ^2) + (0 ^2) by A65, JGRAPH_3:1
.= (q3 `1) ^2 ;
now :: thesis: ( ( q3 `1 = 1 & contradiction ) or ( q3 `1 = - 1 & contradiction ) )end;
hence contradiction ; :: thesis: verum
end;
case A72: t < r ; :: thesis: contradiction
then reconsider B = [.t,r.] as non empty Subset of I[01] by A44, A50, A48, BORSUK_1:40, XXREAL_1:1, XXREAL_2:def 12;
reconsider B0 = B as Subset of I[01] ;
reconsider g = g0 | B0 as Function of (I[01] | B0),R^1 by PRE_TOPC:9;
A73: (q `2) * (p `2) < 0 by A41, A43, XREAL_1:132;
t in { r4 where r4 is Real : ( t <= r4 & r4 <= r ) } by A72;
then t in B by RCOMP_1:def 1;
then A74: p `2 = g . t by A49, FUNCT_1:49;
r in { r4 where r4 is Real : ( t <= r4 & r4 <= r ) } by A72;
then r in B by RCOMP_1:def 1;
then A75: q `2 = g . r by A53, FUNCT_1:49;
g0 is continuous by A36, A15, Th7, Th32;
then A76: g is continuous by TOPMETR:7;
Closed-Interval-TSpace (t,r) = I[01] | B by A38, A52, A72, TOPMETR:20, TOPMETR:23;
then consider r1 being Real such that
A77: g . r1 = 0 and
A78: t < r1 and
A79: r1 < r by A72, A76, A73, A75, A74, TOPREAL5:8;
r1 in { r4 where r4 is Real : ( t <= r4 & r4 <= r ) } by A78, A79;
then A80: r1 in B by RCOMP_1:def 1;
r1 < 1 by A52, A79, XXREAL_0:2;
then r1 in { r2 where r2 is Real : ( 0 <= r2 & r2 <= 1 ) } by A38, A78;
then A81: r1 in dom f by A46, RCOMP_1:def 1;
then f . r1 in rng f by FUNCT_1:def 3;
then f . r1 in R by A34;
then f . r1 in P by A11;
then consider q3 being Point of (TOP-REAL 2) such that
A82: q3 = f . r1 and
A83: |.q3.| = 1 by A3;
A84: q3 `2 = h2 . (f . r1) by A82, PSCOMP_1:def 6
.= (h2 * f) . r1 by A81, FUNCT_1:13
.= 0 by A77, A80, FUNCT_1:49 ;
then A85: 1 ^2 = ((q3 `1) ^2) + (0 ^2) by A83, JGRAPH_3:1
.= (q3 `1) ^2 ;
now :: thesis: ( ( q3 `1 = 1 & contradiction ) or ( q3 `1 = - 1 & contradiction ) )end;
hence contradiction ; :: thesis: verum
end;
end;
end;
hence contradiction ; :: thesis: verum
end;
hence for q being Point of (TOP-REAL 2) st q in Upper_Arc P holds
q `2 >= 0 ; :: thesis: verum
end;
reconsider R = Lower_Arc P as non empty Subset of (TOP-REAL 2) ;
A90: Lower_Arc P is_an_arc_of E-max P, W-min P by A4, JORDAN6:def 9;
then consider f2 being Function of I[01],((TOP-REAL 2) | R) such that
A91: f2 is being_homeomorphism and
A92: f2 . 0 = E-max P and
A93: f2 . 1 = W-min P by TOPREAL1:def 1;
A94: ( dom f2 = the carrier of I[01] & dom h2 = the carrier of (TOP-REAL 2) ) by FUNCT_2:def 1;
A95: rng (h2 * f2) c= the carrier of R^1 ;
A96: the carrier of ((TOP-REAL 2) | R) = R by PRE_TOPC:8;
then rng f2 c= the carrier of (TOP-REAL 2) by XBOOLE_1:1;
then dom (h2 * f2) = the carrier of I[01] by A94, RELAT_1:27;
then reconsider g1 = h2 * f2 as Function of I[01],R^1 by A95, FUNCT_2:2;
A97: f2 is one-to-one by A91, TOPS_2:def 5;
A98: (Upper_Arc P) \/ (Lower_Arc P) = P by A4, JORDAN6:def 9;
then A99: Lower_Arc P c= P by XBOOLE_1:7;
A100: (Lower_Arc P) /\ (Vertical_Line 0) c= {|[0,(- 1)]|,|[0,1]|}
proof
let x be object ; :: according to TARSKI:def 3 :: thesis: ( not x in (Lower_Arc P) /\ (Vertical_Line 0) or x in {|[0,(- 1)]|,|[0,1]|} )
assume A101: x in (Lower_Arc P) /\ (Vertical_Line 0) ; :: thesis: x in {|[0,(- 1)]|,|[0,1]|}
then x in Lower_Arc P by XBOOLE_0:def 4;
then x in P by A98, XBOOLE_0:def 3;
then consider q being Point of (TOP-REAL 2) such that
A102: q = x and
A103: |.q.| = 1 by A3;
x in Vertical_Line 0 by A101, XBOOLE_0:def 4;
then A104: ex p being Point of (TOP-REAL 2) st
( p = x & p `1 = 0 ) ;
then (0 ^2) + ((q `2) ^2) = 1 ^2 by A102, A103, JGRAPH_3:1;
then ( q `2 = 1 or q `2 = - 1 ) by SQUARE_1:41;
then ( x = |[0,(- 1)]| or x = |[0,1]| ) by A104, A102, EUCLID:53;
hence x in {|[0,(- 1)]|,|[0,1]|} by TARSKI:def 2; :: thesis: verum
end;
A105: for p being Point of (TOP-REAL 2) holds h2 . p = proj2 . p ;
A106: f2 is continuous by A91, TOPS_2:def 5;
A107: ( ex p being Point of (TOP-REAL 2) ex t being Real st
( 0 < t & t < 1 & f2 . t = p & p `2 > 0 ) implies for q being Point of (TOP-REAL 2) st q in Lower_Arc P holds
q `2 >= 0 )
proof
given p being Point of (TOP-REAL 2), t being Real such that A108: 0 < t and
A109: t < 1 and
A110: f2 . t = p and
A111: p `2 > 0 ; :: thesis: for q being Point of (TOP-REAL 2) st q in Lower_Arc P holds
q `2 >= 0

now :: thesis: for q being Point of (TOP-REAL 2) holds
( not q in Lower_Arc P or not q `2 < 0 )
assume ex q being Point of (TOP-REAL 2) st
( q in Lower_Arc P & q `2 < 0 ) ; :: thesis: contradiction
then consider q being Point of (TOP-REAL 2) such that
A112: q in Lower_Arc P and
A113: q `2 < 0 ;
rng f2 = [#] ((TOP-REAL 2) | R) by A91, TOPS_2:def 5
.= R by PRE_TOPC:def 5 ;
then consider x being object such that
A114: x in dom f2 and
A115: q = f2 . x by A112, FUNCT_1:def 3;
A116: dom f2 = [.0,1.] by BORSUK_1:40, FUNCT_2:def 1;
then A117: x in { r where r is Real : ( 0 <= r & r <= 1 ) } by A114, RCOMP_1:def 1;
t in { v where v is Real : ( 0 <= v & v <= 1 ) } by A108, A109;
then A118: t in [.0,1.] by RCOMP_1:def 1;
then A119: (h2 * f2) . t = h2 . p by A110, A116, FUNCT_1:13
.= p `2 by PSCOMP_1:def 6 ;
consider r being Real such that
A120: x = r and
A121: 0 <= r and
A122: r <= 1 by A117;
A123: (h2 * f2) . r = h2 . q by A114, A115, A120, FUNCT_1:13
.= q `2 by PSCOMP_1:def 6 ;
now :: thesis: ( ( r < t & contradiction ) or ( t < r & contradiction ) or ( t = r & contradiction ) )
per cases ( r < t or t < r or t = r ) by XXREAL_0:1;
case A124: r < t ; :: thesis: contradiction
then reconsider B = [.r,t.] as non empty Subset of I[01] by A114, A120, A118, BORSUK_1:40, XXREAL_1:1, XXREAL_2:def 12;
reconsider B0 = B as Subset of I[01] ;
reconsider g = g1 | B0 as Function of (I[01] | B0),R^1 by PRE_TOPC:9;
A125: (q `2) * (p `2) < 0 by A111, A113, XREAL_1:132;
t in { r4 where r4 is Real : ( r <= r4 & r4 <= t ) } by A124;
then t in B by RCOMP_1:def 1;
then A126: p `2 = g . t by A119, FUNCT_1:49;
r in { r4 where r4 is Real : ( r <= r4 & r4 <= t ) } by A124;
then r in B by RCOMP_1:def 1;
then A127: q `2 = g . r by A123, FUNCT_1:49;
g1 is continuous by A106, A105, Th7, Th32;
then A128: g is continuous by TOPMETR:7;
Closed-Interval-TSpace (r,t) = I[01] | B by A109, A121, A124, TOPMETR:20, TOPMETR:23;
then consider r1 being Real such that
A129: g . r1 = 0 and
A130: r < r1 and
A131: r1 < t by A124, A128, A125, A127, A126, TOPREAL5:8;
r1 in { r4 where r4 is Real : ( r <= r4 & r4 <= t ) } by A130, A131;
then A132: r1 in B by RCOMP_1:def 1;
r1 < 1 by A109, A131, XXREAL_0:2;
then r1 in { r2 where r2 is Real : ( 0 <= r2 & r2 <= 1 ) } by A121, A130;
then A133: r1 in dom f2 by A116, RCOMP_1:def 1;
then f2 . r1 in rng f2 by FUNCT_1:def 3;
then f2 . r1 in R by A96;
then f2 . r1 in P by A99;
then consider q3 being Point of (TOP-REAL 2) such that
A134: q3 = f2 . r1 and
A135: |.q3.| = 1 by A3;
A136: q3 `2 = h2 . (f2 . r1) by A134, PSCOMP_1:def 6
.= (h2 * f2) . r1 by A133, FUNCT_1:13
.= 0 by A129, A132, FUNCT_1:49 ;
then A137: 1 ^2 = ((q3 `1) ^2) + (0 ^2) by A135, JGRAPH_3:1
.= (q3 `1) ^2 ;
now :: thesis: ( ( q3 `1 = 1 & contradiction ) or ( q3 `1 = - 1 & contradiction ) )end;
hence contradiction ; :: thesis: verum
end;
case A142: t < r ; :: thesis: contradiction
then reconsider B = [.t,r.] as non empty Subset of I[01] by A114, A120, A118, BORSUK_1:40, XXREAL_1:1, XXREAL_2:def 12;
reconsider B0 = B as Subset of I[01] ;
reconsider g = g1 | B0 as Function of (I[01] | B0),R^1 by PRE_TOPC:9;
A143: (q `2) * (p `2) < 0 by A111, A113, XREAL_1:132;
t in { r4 where r4 is Real : ( t <= r4 & r4 <= r ) } by A142;
then t in B by RCOMP_1:def 1;
then A144: p `2 = g . t by A119, FUNCT_1:49;
r in { r4 where r4 is Real : ( t <= r4 & r4 <= r ) } by A142;
then r in B by RCOMP_1:def 1;
then A145: q `2 = g . r by A123, FUNCT_1:49;
g1 is continuous by A106, A105, Th7, Th32;
then A146: g is continuous by TOPMETR:7;
Closed-Interval-TSpace (t,r) = I[01] | B by A108, A122, A142, TOPMETR:20, TOPMETR:23;
then consider r1 being Real such that
A147: g . r1 = 0 and
A148: t < r1 and
A149: r1 < r by A142, A146, A143, A145, A144, TOPREAL5:8;
r1 in { r4 where r4 is Real : ( t <= r4 & r4 <= r ) } by A148, A149;
then A150: r1 in B by RCOMP_1:def 1;
r1 < 1 by A122, A149, XXREAL_0:2;
then r1 in { r2 where r2 is Real : ( 0 <= r2 & r2 <= 1 ) } by A108, A148;
then A151: r1 in dom f2 by A116, RCOMP_1:def 1;
then f2 . r1 in rng f2 by FUNCT_1:def 3;
then f2 . r1 in R by A96;
then f2 . r1 in P by A99;
then consider q3 being Point of (TOP-REAL 2) such that
A152: q3 = f2 . r1 and
A153: |.q3.| = 1 by A3;
A154: q3 `2 = h2 . (f2 . r1) by A152, PSCOMP_1:def 6
.= g1 . r1 by A151, FUNCT_1:13
.= 0 by A147, A150, FUNCT_1:49 ;
then A155: 1 ^2 = ((q3 `1) ^2) + (0 ^2) by A153, JGRAPH_3:1
.= (q3 `1) ^2 ;
now :: thesis: ( ( q3 `1 = 1 & contradiction ) or ( q3 `1 = - 1 & contradiction ) )end;
hence contradiction ; :: thesis: verum
end;
end;
end;
hence contradiction ; :: thesis: verum
end;
hence for q being Point of (TOP-REAL 2) st q in Lower_Arc P holds
q `2 >= 0 ; :: thesis: verum
end;
W-min P in {(W-min P),(E-max P)} by TARSKI:def 2;
then A160: W-min P in Upper_Arc P by A10, XBOOLE_0:def 4;
A161: ( W-bound P = - 1 & E-bound P = 1 ) by A3, Th28;
now :: thesis: not r8 = 1end;
then A162: 1 > r8 by A25, XXREAL_0:1;
Lower_Arc P is closed by A90, JORDAN6:11;
then (Lower_Arc P) /\ (Vertical_Line 0) is closed by A26, TOPS_1:8;
then Last_Point ((Lower_Arc P),(E-max P),(W-min P),(Vertical_Line 0)) in (Lower_Arc P) /\ (Vertical_Line 0) by A90, A18, JORDAN5C:def 2;
then A163: ( Last_Point ((Lower_Arc P),(E-max P),(W-min P),(Vertical_Line 0)) = |[0,(- 1)]| or Last_Point ((Lower_Arc P),(E-max P),(W-min P),(Vertical_Line 0)) = |[0,1]| ) by A100, TARSKI:def 2;
E-max P in {(W-min P),(E-max P)} by TARSKI:def 2;
then A164: E-max P in Upper_Arc P by A10, XBOOLE_0:def 4;
A165: { p where p is Point of (TOP-REAL 2) : ( p in P & p `2 >= 0 ) } c= Upper_Arc P
proof
let x be object ; :: according to TARSKI:def 3 :: thesis: ( not x in { p where p is Point of (TOP-REAL 2) : ( p in P & p `2 >= 0 ) } or x in Upper_Arc P )
assume x in { p where p is Point of (TOP-REAL 2) : ( p in P & p `2 >= 0 ) } ; :: thesis: x in Upper_Arc P
then consider p being Point of (TOP-REAL 2) such that
A166: p = x and
A167: p in P and
A168: p `2 >= 0 ;
now :: thesis: ( ( p `2 = 0 & x in Upper_Arc P ) or ( p `2 > 0 & x in Upper_Arc P ) )
per cases ( p `2 = 0 or p `2 > 0 ) by A168;
case A169: p `2 = 0 ; :: thesis: x in Upper_Arc P
ex p8 being Point of (TOP-REAL 2) st
( p8 = p & |.p8.| = 1 ) by A3, A167;
then 1 = sqrt (((p `1) ^2) + ((p `2) ^2)) by JGRAPH_3:1
.= |.(p `1).| by A169, COMPLEX1:72 ;
then ( p = |[(p `1),(p `2)]| & (p `1) ^2 = 1 ^2 ) by COMPLEX1:75, EUCLID:53;
then ( p = |[1,0]| or p = |[(- 1),0]| ) by A169, SQUARE_1:41;
hence x in Upper_Arc P by A3, A164, A160, A166, Th29, Th30; :: thesis: verum
end;
case A170: p `2 > 0 ; :: thesis: x in Upper_Arc P
now :: thesis: x in Upper_Arc P
assume not x in Upper_Arc P ; :: thesis: contradiction
then A171: x in Lower_Arc P by A98, A166, A167, XBOOLE_0:def 3;
rng f2 = [#] ((TOP-REAL 2) | R) by A91, TOPS_2:def 5
.= R by PRE_TOPC:def 5 ;
then consider x2 being object such that
A172: x2 in dom f2 and
A173: p = f2 . x2 by A166, A171, FUNCT_1:def 3;
dom f2 = [.0,1.] by BORSUK_1:40, FUNCT_2:def 1;
then x2 in { r where r is Real : ( 0 <= r & r <= 1 ) } by A172, RCOMP_1:def 1;
then consider t2 being Real such that
A174: x2 = t2 and
A175: 0 <= t2 and
A176: t2 <= 1 ;
A177: |[0,(- 1)]| `2 = - 1 by EUCLID:52;
now :: thesis: not t2 = 1end;
then A178: t2 < 1 by A176, XXREAL_0:1;
A179: now :: thesis: not t2 = 0 end;
|[0,(- 1)]| `1 = 0 by EUCLID:52;
then |.|[0,(- 1)]|.| = sqrt ((0 ^2) + ((- 1) ^2)) by A177, JGRAPH_3:1
.= 1 ;
then A180: |[0,(- 1)]| in { q where q is Point of (TOP-REAL 2) : |.q.| = 1 } ;
now :: thesis: ( ( |[0,(- 1)]| in Upper_Arc P & contradiction ) or ( |[0,(- 1)]| in Lower_Arc P & contradiction ) )end;
hence contradiction ; :: thesis: verum
end;
hence x in Upper_Arc P ; :: thesis: verum
end;
end;
end;
hence x in Upper_Arc P ; :: thesis: verum
end;
Upper_Arc P c= { p where p is Point of (TOP-REAL 2) : ( p in P & p `2 >= 0 ) }
proof
let x2 be object ; :: according to TARSKI:def 3 :: thesis: ( not x2 in Upper_Arc P or x2 in { p where p is Point of (TOP-REAL 2) : ( p in P & p `2 >= 0 ) } )
assume A181: x2 in Upper_Arc P ; :: thesis: x2 in { p where p is Point of (TOP-REAL 2) : ( p in P & p `2 >= 0 ) }
then reconsider q3 = x2 as Point of (TOP-REAL 2) ;
q3 `2 >= 0 by A19, A161, A31, A163, A22, A23, A24, A32, A162, A37, A181, EUCLID:52;
hence x2 in { p where p is Point of (TOP-REAL 2) : ( p in P & p `2 >= 0 ) } by A11, A181; :: thesis: verum
end;
hence Upper_Arc P = { p where p is Point of (TOP-REAL 2) : ( p in P & p `2 >= 0 ) } by A165, XBOOLE_0:def 10; :: thesis: verum