:: TOPREALB semantic presentation
set c1 = 2 * PI ;
set c2 = |[0,0]|;
set c3 = the carrier of R^1 ;
Lemma1:
0 in INT
by INT_1:def 1;
reconsider c4 = - 1 as real negative number ;
reconsider c5 = 1 as real positive number ;
set c6 = Closed-Interval-TSpace (- 1),1;
set c7 = the carrier of (Closed-Interval-TSpace (- 1),1);
Lemma2:
the carrier of (Closed-Interval-TSpace (- 1),1) = [.(- 1),1.]
by TOPMETR:25;
Lemma3:
1 - 0 <= 1
;
Lemma4:
(3 / 2) - (1 / 2) <= 1
;
Lemma5:
PI / 2 < PI / 1
by REAL_2:200;
Lemma6:
1 * PI < (3 / 2) * PI
by XREAL_1:70;
Lemma7:
(3 / 2) * PI < 2 * PI
by XREAL_1:70;
Lemma8:
dom sin = REAL
by SIN_COS:def 20;
Lemma9:
for b1 being non empty TopSpace
for b2 being non empty SubSpace of b1
for b3 being non empty SubSpace of b2
for b4 being Point of b3 holds b4 is Point of b1
Lemma10:
for b1 being TopSpace
for b2 being SubSpace of b1
for b3 being SubSpace of b2
for b4 being Subset of b3 holds b4 is Subset of b1
theorem Th1: :: TOPREALB:1
theorem Th2: :: TOPREALB:2
:: deftheorem Def1 defines IntIntervals TOPREALB:def 1 :
theorem Th3: :: TOPREALB:3
theorem Th4: :: TOPREALB:4
:: deftheorem Def2 defines R^1 TOPREALB:def 2 :
:: deftheorem Def3 defines R^1 TOPREALB:def 3 :
:: deftheorem Def4 defines R^1 TOPREALB:def 4 :
theorem Th5: :: TOPREALB:5
theorem Th6: :: TOPREALB:6
theorem Th7: :: TOPREALB:7
theorem Th8: :: TOPREALB:8
Lemma17:
sin is Function of R^1 ,R^1
Lemma18:
cos is Function of R^1 ,R^1
set c8 = R^1 ].0,1.[;
:: deftheorem Def5 defines being_simple_closed_curve TOPREALB:def 5 :
:: deftheorem Def6 defines Tcircle TOPREALB:def 6 :
theorem Th9: :: TOPREALB:9
theorem Th10: :: TOPREALB:10
theorem Th11: :: TOPREALB:11
:: deftheorem Def7 defines Tunit_circle TOPREALB:def 7 :
set c9 = Tunit_circle 2;
set c10 = the carrier of (Tunit_circle 2);
Lemma23:
the carrier of (Tunit_circle 2) = Sphere |[0,0]|,1
by Th9, EUCLID:58;
theorem Th12: :: TOPREALB:12
theorem Th13: :: TOPREALB:13
theorem Th14: :: TOPREALB:14
theorem Th15: :: TOPREALB:15
theorem Th16: :: TOPREALB:16
theorem Th17: :: TOPREALB:17
set c11 = Trectangle c4,c5,c4,c5;
theorem Th18: :: TOPREALB:18
theorem Th19: :: TOPREALB:19
Lemma29:
for b1 being non empty Nat
for b2 being real positive number
for b3 being Point of (TOP-REAL b1) holds Tunit_circle b1, Tcircle b3,b2 are_homeomorphic
theorem Th20: :: TOPREALB:20
:: deftheorem Def8 defines c[10] TOPREALB:def 8 :
:: deftheorem Def9 defines c[-10] TOPREALB:def 9 :
theorem Th21: :: TOPREALB:21
:: deftheorem Def10 defines Topen_unit_circle TOPREALB:def 10 :
theorem Th22: :: TOPREALB:22
theorem Th23: :: TOPREALB:23
theorem Th24: :: TOPREALB:24
theorem Th25: :: TOPREALB:25
theorem Th26: :: TOPREALB:26
set c12 = Topen_unit_circle c[10] ;
set c13 = Topen_unit_circle c[-10] ;
set c14 = the carrier of (Topen_unit_circle c[10] );
set c15 = the carrier of (Topen_unit_circle c[-10] );
set c16 = the carrier of (R^1 | (R^1 ].0,(0 + c5).[));
set c17 = the carrier of (R^1 | (R^1 ].(1 / 2),((1 / 2) + c5).[));
Lemma37:
the carrier of (Topen_unit_circle c[10] ) = [#] (Topen_unit_circle c[10] )
;
Lemma38:
the carrier of (Topen_unit_circle c[-10] ) = [#] (Topen_unit_circle c[-10] )
;
theorem Th27: :: TOPREALB:27
theorem Th28: :: TOPREALB:28
theorem Th29: :: TOPREALB:29
theorem Th30: :: TOPREALB:30
theorem Th31: :: TOPREALB:31
:: deftheorem Def11 defines CircleMap TOPREALB:def 11 :
Lemma43:
dom CircleMap = REAL
by FUNCT_2:def 1, TOPMETR:24;
theorem Th32: :: TOPREALB:32
theorem Th33: :: TOPREALB:33
theorem Th34: :: TOPREALB:34
Lemma47:
CircleMap . (1 / 2) = |[(- 1),0]|
Lemma48:
CircleMap . 1 = |[1,0]|
by Th33;
theorem Th35: :: TOPREALB:35
theorem Th36: :: TOPREALB:36
theorem Th37: :: TOPREALB:37
Lemma50:
for b1 being real number holds CircleMap . b1 = |[((cos * (AffineMap (2 * PI ),0)) . b1),((sin * (AffineMap (2 * PI ),0)) . b1)]|
theorem Th38: :: TOPREALB:38
Lemma51:
for b1 being Subset of R^1 holds CircleMap | b1 is Function of (R^1 | b1),(Tunit_circle 2)
Lemma52:
for b1 being real number st - 1 <= b1 & b1 <= 1 holds
( 0 <= (arccos b1) / (2 * PI ) & (arccos b1) / (2 * PI ) <= 1 / 2 )
theorem Th39: :: TOPREALB:39
Lemma54:
CircleMap | [.0,1.[ is one-to-one
theorem Th40: :: TOPREALB:40
theorem Th41: :: TOPREALB:41
:: deftheorem Def12 defines CircleMap TOPREALB:def 12 :
Lemma57:
for b1, b2 being real number holds rng ((AffineMap 1,(- b1)) | ].(b2 + b1),((b2 + b1) + 1).[) = ].b2,(b2 + 1).[
theorem Th42: :: TOPREALB:42
definition
func Circle2IntervalR -> Function of
(Topen_unit_circle c[10] ),
(R^1 | (R^1 ].0,1.[)) means :
Def13:
:: TOPREALB:def 13
for
b1 being
Point of
(Topen_unit_circle c[10] ) ex
b2,
b3 being
real number st
(
b1 = |[b2,b3]| & (
b3 >= 0 implies
a1 . b1 = (arccos b2) / (2 * PI ) ) & (
b3 <= 0 implies
a1 . b1 = 1
- ((arccos b2) / (2 * PI )) ) );
existence
ex b1 being Function of (Topen_unit_circle c[10] ),(R^1 | (R^1 ].0,1.[)) st
for b2 being Point of (Topen_unit_circle c[10] ) ex b3, b4 being real number st
( b2 = |[b3,b4]| & ( b4 >= 0 implies b1 . b2 = (arccos b3) / (2 * PI ) ) & ( b4 <= 0 implies b1 . b2 = 1 - ((arccos b3) / (2 * PI )) ) )
uniqueness
for b1, b2 being Function of (Topen_unit_circle c[10] ),(R^1 | (R^1 ].0,1.[)) st ( for b3 being Point of (Topen_unit_circle c[10] ) ex b4, b5 being real number st
( b3 = |[b4,b5]| & ( b5 >= 0 implies b1 . b3 = (arccos b4) / (2 * PI ) ) & ( b5 <= 0 implies b1 . b3 = 1 - ((arccos b4) / (2 * PI )) ) ) ) & ( for b3 being Point of (Topen_unit_circle c[10] ) ex b4, b5 being real number st
( b3 = |[b4,b5]| & ( b5 >= 0 implies b2 . b3 = (arccos b4) / (2 * PI ) ) & ( b5 <= 0 implies b2 . b3 = 1 - ((arccos b4) / (2 * PI )) ) ) ) holds
b1 = b2
end;
:: deftheorem Def13 defines Circle2IntervalR TOPREALB:def 13 :
set c18 = R^1 ].(1 / 2),((1 / 2) + c5).[;
definition
func Circle2IntervalL -> Function of
(Topen_unit_circle c[-10] ),
(R^1 | (R^1 ].(1 / 2),(3 / 2).[)) means :
Def14:
:: TOPREALB:def 14
for
b1 being
Point of
(Topen_unit_circle c[-10] ) ex
b2,
b3 being
real number st
(
b1 = |[b2,b3]| & (
b3 >= 0 implies
a1 . b1 = 1
+ ((arccos b2) / (2 * PI )) ) & (
b3 <= 0 implies
a1 . b1 = 1
- ((arccos b2) / (2 * PI )) ) );
existence
ex b1 being Function of (Topen_unit_circle c[-10] ),(R^1 | (R^1 ].(1 / 2),(3 / 2).[)) st
for b2 being Point of (Topen_unit_circle c[-10] ) ex b3, b4 being real number st
( b2 = |[b3,b4]| & ( b4 >= 0 implies b1 . b2 = 1 + ((arccos b3) / (2 * PI )) ) & ( b4 <= 0 implies b1 . b2 = 1 - ((arccos b3) / (2 * PI )) ) )
uniqueness
for b1, b2 being Function of (Topen_unit_circle c[-10] ),(R^1 | (R^1 ].(1 / 2),(3 / 2).[)) st ( for b3 being Point of (Topen_unit_circle c[-10] ) ex b4, b5 being real number st
( b3 = |[b4,b5]| & ( b5 >= 0 implies b1 . b3 = 1 + ((arccos b4) / (2 * PI )) ) & ( b5 <= 0 implies b1 . b3 = 1 - ((arccos b4) / (2 * PI )) ) ) ) & ( for b3 being Point of (Topen_unit_circle c[-10] ) ex b4, b5 being real number st
( b3 = |[b4,b5]| & ( b5 >= 0 implies b2 . b3 = 1 + ((arccos b4) / (2 * PI )) ) & ( b5 <= 0 implies b2 . b3 = 1 - ((arccos b4) / (2 * PI )) ) ) ) holds
b1 = b2
end;
:: deftheorem Def14 defines Circle2IntervalL TOPREALB:def 14 :
set c19 = Circle2IntervalR ;
set c20 = Circle2IntervalL ;
theorem Th43: :: TOPREALB:43
theorem Th44: :: TOPREALB:44
set c21 = ].0,1.[;
set c22 = [.(- 1),1.[;
set c23 = ].0,PI .];
set c24 = 1 / (2 * PI );
reconsider c25 = [.(- 1),1.[, c26 = ].0,PI .] as non empty Subset of REAL ;
Lemma63:
the carrier of (R^1 | (R^1 c25)) = R^1 c25
by JORDAN1:1;
Lemma64:
the carrier of (R^1 | (R^1 c26)) = R^1 c26
by JORDAN1:1;
Lemma65:
the carrier of (R^1 | (R^1 ].0,1.[)) = R^1 ].0,1.[
by JORDAN1:1;
set c27 = (AffineMap (1 / (2 * PI )),0) | (R^1 c26);
dom (AffineMap (1 / (2 * PI )),0) = the carrier of R^1
by FUNCT_2:def 1, TOPMETR:24;
then Lemma66:
dom ((AffineMap (1 / (2 * PI )),0) | (R^1 c26)) = R^1 c26
by RELAT_1:91;
rng ((AffineMap (1 / (2 * PI )),0) | (R^1 c26)) c= ].0,1.[
then reconsider c28 = (AffineMap (1 / (2 * PI )),0) | (R^1 c26) as Function of (R^1 | (R^1 c26)),(R^1 | (R^1 ].0,1.[)) by Lemma64, Lemma65, Lemma66, FUNCT_2:4;
Lemma67:
R^1 (AffineMap (1 / (2 * PI )),0) = AffineMap (1 / (2 * PI )),0
;
Lemma68:
dom (AffineMap (1 / (2 * PI )),0) = REAL
by FUNCT_2:def 1;
Lemma69:
rng (AffineMap (1 / (2 * PI )),0) = REAL
by JORDAN16:32;
Lemma70:
[#] R^1 = REAL
by TOPMETR:24;
R^1 | ([#] R^1 ) = R^1
by TSEP_1:3;
then
( R^1 = R^1 | (R^1 (dom (AffineMap (1 / (2 * PI )),0))) & R^1 = R^1 | (R^1 (rng (AffineMap (1 / (2 * PI )),0))) )
by Lemma68, Lemma69, Lemma70;
then reconsider c29 = c28 as continuous Function of (R^1 | (R^1 c26)),(R^1 | (R^1 ].0,1.[)) by Lemma67, TOPREALA:29;
set c30 = (R^1 (AffineMap (- 1),1)) | (R^1 ].0,1.[);
Lemma71:
dom (AffineMap (- 1),1) = REAL
by FUNCT_2:def 1;
then Lemma72:
dom ((R^1 (AffineMap (- 1),1)) | (R^1 ].0,1.[)) = ].0,1.[
by RELAT_1:91;
rng ((R^1 (AffineMap (- 1),1)) | (R^1 ].0,1.[)) c= ].0,1.[
then reconsider c31 = (R^1 (AffineMap (- 1),1)) | (R^1 ].0,1.[) as Function of (R^1 | (R^1 ].0,1.[)),(R^1 | (R^1 ].0,1.[)) by Lemma65, Lemma72, FUNCT_2:4;
Lemma73:
rng (AffineMap (- 1),1) = REAL
by JORDAN16:32;
Lemma74:
[#] R^1 = REAL
by TOPMETR:24;
Lemma75:
R^1 | ([#] R^1 ) = R^1
by TSEP_1:3;
then
( R^1 = R^1 | (R^1 (dom (AffineMap (- 1),1))) & R^1 = R^1 | (R^1 (rng (AffineMap (- 1),1))) )
by Lemma71, Lemma73, Lemma74;
then reconsider c32 = c31 as continuous Function of (R^1 | (R^1 ].0,1.[)),(R^1 | (R^1 ].0,1.[)) by TOPREALA:29;
reconsider c33 = R^1 arccos as continuous Function of (R^1 | (R^1 [.(- 1),1.])),(R^1 | (R^1 [.0,PI .])) by SIN_COS6:87, SIN_COS6:88;
set c34 = c33 | (R^1 c25);
c25 c= [.(- 1),1.]
by TOPREALA:11;
then Lemma76:
dom (c33 | (R^1 c25)) = c25
by RELAT_1:91, SIN_COS6:88;
Lemma77:
rng (c33 | (R^1 c25)) c= c26
then reconsider c35 = c33 | (R^1 c25) as Function of (R^1 | (R^1 c25)),(R^1 | (R^1 c26)) by Lemma63, Lemma64, Lemma76, FUNCT_2:4;
the carrier of (R^1 | (R^1 [.(- 1),1.])) =
R^1 [.(- 1),1.]
by JORDAN1:1
.=
[.(- 1),1.]
;
then reconsider c36 = R^1 c25 as Subset of (R^1 | (R^1 [.(- 1),1.])) by TOPREALA:11;
the carrier of (R^1 | (R^1 [.0,PI .])) =
R^1 [.0,PI .]
by JORDAN1:1
.=
[.0,PI .]
;
then reconsider c37 = R^1 c26 as Subset of (R^1 | (R^1 [.0,PI .])) by TOPREALA:15;
( (R^1 | (R^1 [.(- 1),1.])) | c36 = R^1 | (R^1 c25) & (R^1 | (R^1 [.0,PI .])) | c37 = R^1 | (R^1 c26) )
by GOBOARD9:4;
then Lemma78:
c35 is continuous
by TOPREALA:29;
reconsider c38 = proj1 as Function of (TOP-REAL 2),R^1 by TOPMETR:24;
Lemma79:
dom c38 = the carrier of (TOP-REAL 2)
by FUNCT_2:def 1;
Lemma80:
c38 is continuous
by TOPREAL6:83;
Lemma81:
for b1 being Subset of (Topen_unit_circle c[10] ) st b1 = { b2 where B is Point of (TOP-REAL 2) : ( b2 in the carrier of (Topen_unit_circle c[10] ) & 0 <= b2 `2 ) } holds
Circle2IntervalR | ((Topen_unit_circle c[10] ) | b1) is continuous
Lemma82:
for b1 being Subset of (Topen_unit_circle c[10] ) st b1 = { b2 where B is Point of (TOP-REAL 2) : ( b2 in the carrier of (Topen_unit_circle c[10] ) & 0 >= b2 `2 ) } holds
Circle2IntervalR | ((Topen_unit_circle c[10] ) | b1) is continuous
Lemma83:
for b1 being Point of (Topen_unit_circle c[10] ) st b1 = c[-10] holds
Circle2IntervalR is_continuous_at b1
set c39 = REAL --> 1;
Lemma84:
dom (REAL --> 1) = REAL
by FUNCOP_1:19;
rng (REAL --> 1) c= REAL
by XBOOLE_1:1;
then reconsider c40 = REAL --> 1 as PartFunc of REAL , REAL by Lemma84, RELSET_1:11;
Lemma85:
Circle2IntervalR is continuous
set c41 = ].(1 / 2),((1 / 2) + c5).[;
set c42 = ].(- 1),1.];
set c43 = [.0,PI .[;
reconsider c44 = ].(- 1),1.], c45 = [.0,PI .[ as non empty Subset of REAL ;
Lemma86:
the carrier of (R^1 | (R^1 c44)) = R^1 c44
by JORDAN1:1;
Lemma87:
the carrier of (R^1 | (R^1 c45)) = R^1 c45
by JORDAN1:1;
Lemma88:
the carrier of (R^1 | (R^1 ].(1 / 2),((1 / 2) + c5).[)) = R^1 ].(1 / 2),((1 / 2) + c5).[
by JORDAN1:1;
set c46 = (AffineMap (- (1 / (2 * PI ))),1) | (R^1 c45);
dom (AffineMap (- (1 / (2 * PI ))),1) = the carrier of R^1
by FUNCT_2:def 1, TOPMETR:24;
then Lemma89:
dom ((AffineMap (- (1 / (2 * PI ))),1) | (R^1 c45)) = R^1 c45
by RELAT_1:91;
rng ((AffineMap (- (1 / (2 * PI ))),1) | (R^1 c45)) c= ].(1 / 2),((1 / 2) + c5).[
then reconsider c47 = (AffineMap (- (1 / (2 * PI ))),1) | (R^1 c45) as Function of (R^1 | (R^1 c45)),(R^1 | (R^1 ].(1 / 2),((1 / 2) + c5).[)) by Lemma87, Lemma88, Lemma89, FUNCT_2:4;
Lemma90:
R^1 (AffineMap (- (1 / (2 * PI ))),1) = AffineMap (- (1 / (2 * PI ))),1
;
Lemma91:
dom (AffineMap (- (1 / (2 * PI ))),1) = REAL
by FUNCT_2:def 1;
rng (AffineMap (- (1 / (2 * PI ))),1) = REAL
by JORDAN16:32;
then
( R^1 = R^1 | (R^1 (dom (AffineMap (- (1 / (2 * PI ))),1))) & R^1 = R^1 | (R^1 (rng (AffineMap (- (1 / (2 * PI ))),1))) )
by Lemma74, Lemma75, Lemma91;
then reconsider c48 = c47 as continuous Function of (R^1 | (R^1 c45)),(R^1 | (R^1 ].(1 / 2),((1 / 2) + c5).[)) by Lemma90, TOPREALA:29;
set c49 = (AffineMap (1 / (2 * PI )),1) | (R^1 c45);
dom (AffineMap (1 / (2 * PI )),1) = the carrier of R^1
by FUNCT_2:def 1, TOPMETR:24;
then Lemma92:
dom ((AffineMap (1 / (2 * PI )),1) | (R^1 c45)) = R^1 c45
by RELAT_1:91;
rng ((AffineMap (1 / (2 * PI )),1) | (R^1 c45)) c= ].(1 / 2),((1 / 2) + c5).[
then reconsider c50 = (AffineMap (1 / (2 * PI )),1) | (R^1 c45) as Function of (R^1 | (R^1 c45)),(R^1 | (R^1 ].(1 / 2),((1 / 2) + c5).[)) by Lemma87, Lemma88, Lemma92, FUNCT_2:4;
Lemma93:
R^1 (AffineMap (1 / (2 * PI )),1) = AffineMap (1 / (2 * PI )),1
;
Lemma94:
dom (AffineMap (1 / (2 * PI )),1) = REAL
by FUNCT_2:def 1;
rng (AffineMap (1 / (2 * PI )),1) = REAL
by JORDAN16:32;
then
( R^1 = R^1 | (R^1 (dom (AffineMap (1 / (2 * PI )),1))) & R^1 = R^1 | (R^1 (rng (AffineMap (1 / (2 * PI )),1))) )
by Lemma74, Lemma75, Lemma94;
then reconsider c51 = c50 as continuous Function of (R^1 | (R^1 c45)),(R^1 | (R^1 ].(1 / 2),((1 / 2) + c5).[)) by Lemma93, TOPREALA:29;
set c52 = c33 | (R^1 c44);
c44 c= [.(- 1),1.]
by TOPREALA:15;
then Lemma95:
dom (c33 | (R^1 c44)) = c44
by RELAT_1:91, SIN_COS6:88;
Lemma96:
rng (c33 | (R^1 c44)) c= c45
then reconsider c53 = c33 | (R^1 c44) as Function of (R^1 | (R^1 c44)),(R^1 | (R^1 c45)) by Lemma86, Lemma87, Lemma95, FUNCT_2:4;
the carrier of (R^1 | (R^1 [.(- 1),1.])) =
R^1 [.(- 1),1.]
by JORDAN1:1
.=
[.(- 1),1.]
;
then reconsider c54 = R^1 c44 as Subset of (R^1 | (R^1 [.(- 1),1.])) by TOPREALA:15;
the carrier of (R^1 | (R^1 [.0,PI .])) =
R^1 [.0,PI .]
by JORDAN1:1
.=
[.0,PI .]
;
then reconsider c55 = R^1 c45 as Subset of (R^1 | (R^1 [.0,PI .])) by TOPREALA:11;
( (R^1 | (R^1 [.(- 1),1.])) | c54 = R^1 | (R^1 c44) & (R^1 | (R^1 [.0,PI .])) | c55 = R^1 | (R^1 c45) )
by GOBOARD9:4;
then Lemma97:
c53 is continuous
by TOPREALA:29;
Lemma98:
for b1 being Subset of (Topen_unit_circle c[-10] ) st b1 = { b2 where B is Point of (TOP-REAL 2) : ( b2 in the carrier of (Topen_unit_circle c[-10] ) & 0 <= b2 `2 ) } holds
Circle2IntervalL | ((Topen_unit_circle c[-10] ) | b1) is continuous
Lemma99:
for b1 being Subset of (Topen_unit_circle c[-10] ) st b1 = { b2 where B is Point of (TOP-REAL 2) : ( b2 in the carrier of (Topen_unit_circle c[-10] ) & 0 >= b2 `2 ) } holds
Circle2IntervalL | ((Topen_unit_circle c[-10] ) | b1) is continuous
Lemma100:
for b1 being Point of (Topen_unit_circle c[-10] ) st b1 = c[10] holds
Circle2IntervalL is_continuous_at b1
Lemma101:
Circle2IntervalL is continuous
Lemma102:
CircleMap (R^1 0) is open
Lemma103:
CircleMap (R^1 (1 / 2)) is open
by Lemma47, Th44, TOPREALA:35;
theorem Th45: :: TOPREALB:45
canceled;
theorem Th46: :: TOPREALB:46
theorem Th47: :: TOPREALB:47
canceled;
theorem Th48: :: TOPREALB:48
canceled;
theorem Th49: :: TOPREALB:49
ex
b1 being
Subset-Family of
(Tunit_circle 2) st
(
b1 = {(CircleMap .: ].0,1.[),(CircleMap .: ].(1 / 2),(3 / 2).[)} &
b1 is_a_cover_of Tunit_circle 2 &
b1 is
open & ( for
b2 being
Subset of
(Tunit_circle 2) holds
( (
b2 = CircleMap .: ].0,1.[ implies (
union (IntIntervals 0,1) = CircleMap " b2 & ( for
b3 being
Subset of
R^1 st
b3 in IntIntervals 0,1 holds
for
b4 being
Function of
(R^1 | b3),
((Tunit_circle 2) | b2) st
b4 = CircleMap | b3 holds
b4 is_homeomorphism ) ) ) & (
b2 = CircleMap .: ].(1 / 2),(3 / 2).[ implies (
union (IntIntervals (1 / 2),(3 / 2)) = CircleMap " b2 & ( for
b3 being
Subset of
R^1 st
b3 in IntIntervals (1 / 2),
(3 / 2) holds
for
b4 being
Function of
(R^1 | b3),
((Tunit_circle 2) | b2) st
b4 = CircleMap | b3 holds
b4 is_homeomorphism ) ) ) ) ) )