:: BORSUK_5 semantic presentation

theorem Th1: :: BORSUK_5:1
canceled;

theorem Th2: :: BORSUK_5:2
for b1, b2, b3 being set st b1 c= b2 & b2 c= b1 \/ {b3} & not b1 \/ {b3} = b2 holds
b1 = b2
proof end;

theorem Th3: :: BORSUK_5:3
for b1, b2, b3, b4, b5, b6 being set holds {b1,b2,b3,b4,b5,b6} = {b1,b3,b6} \/ {b2,b4,b5}
proof end;

definition
let c1, c2, c3, c4, c5, c6 be set ;
pred c1,c2,c3,c4,c5,c6 are_mutually_different means :Def1: :: BORSUK_5:def 1
( a1 <> a2 & a1 <> a3 & a1 <> a4 & a1 <> a5 & a1 <> a6 & a2 <> a3 & a2 <> a4 & a2 <> a5 & a2 <> a6 & a3 <> a4 & a3 <> a5 & a3 <> a6 & a4 <> a5 & a4 <> a6 & a5 <> a6 );
end;

:: deftheorem Def1 defines are_mutually_different BORSUK_5:def 1 :
for b1, b2, b3, b4, b5, b6 being set holds
( b1,b2,b3,b4,b5,b6 are_mutually_different iff ( b1 <> b2 & b1 <> b3 & b1 <> b4 & b1 <> b5 & b1 <> b6 & b2 <> b3 & b2 <> b4 & b2 <> b5 & b2 <> b6 & b3 <> b4 & b3 <> b5 & b3 <> b6 & b4 <> b5 & b4 <> b6 & b5 <> b6 ) );

definition
let c1, c2, c3, c4, c5, c6, c7 be set ;
pred c1,c2,c3,c4,c5,c6,c7 are_mutually_different means :Def2: :: BORSUK_5:def 2
( a1 <> a2 & a1 <> a3 & a1 <> a4 & a1 <> a5 & a1 <> a6 & a1 <> a7 & a2 <> a3 & a2 <> a4 & a2 <> a5 & a2 <> a6 & a2 <> a7 & a3 <> a4 & a3 <> a5 & a3 <> a6 & a3 <> a7 & a4 <> a5 & a4 <> a6 & a4 <> a7 & a5 <> a6 & a5 <> a7 & a6 <> a7 );
end;

:: deftheorem Def2 defines are_mutually_different BORSUK_5:def 2 :
for b1, b2, b3, b4, b5, b6, b7 being set holds
( b1,b2,b3,b4,b5,b6,b7 are_mutually_different iff ( b1 <> b2 & b1 <> b3 & b1 <> b4 & b1 <> b5 & b1 <> b6 & b1 <> b7 & b2 <> b3 & b2 <> b4 & b2 <> b5 & b2 <> b6 & b2 <> b7 & b3 <> b4 & b3 <> b5 & b3 <> b6 & b3 <> b7 & b4 <> b5 & b4 <> b6 & b4 <> b7 & b5 <> b6 & b5 <> b7 & b6 <> b7 ) );

theorem Th4: :: BORSUK_5:4
for b1, b2, b3, b4, b5, b6 being set st b1,b2,b3,b4,b5,b6 are_mutually_different holds
card {b1,b2,b3,b4,b5,b6} = 6
proof end;

theorem Th5: :: BORSUK_5:5
for b1, b2, b3, b4, b5, b6, b7 being set st b1,b2,b3,b4,b5,b6,b7 are_mutually_different holds
card {b1,b2,b3,b4,b5,b6,b7} = 7
proof end;

theorem Th6: :: BORSUK_5:6
for b1, b2, b3, b4, b5, b6 being set st {b1,b2,b3} misses {b4,b5,b6} holds
( b1 <> b4 & b1 <> b5 & b1 <> b6 & b2 <> b4 & b2 <> b5 & b2 <> b6 & b3 <> b4 & b3 <> b5 & b3 <> b6 )
proof end;

theorem Th7: :: BORSUK_5:7
for b1, b2, b3, b4, b5, b6 being set st b1,b2,b3 are_mutually_different & b4,b5,b6 are_mutually_different & {b1,b2,b3} misses {b4,b5,b6} holds
b1,b2,b3,b4,b5,b6 are_mutually_different
proof end;

theorem Th8: :: BORSUK_5:8
for b1, b2, b3, b4, b5, b6, b7 being set st b1,b2,b3,b4,b5,b6 are_mutually_different & {b1,b2,b3,b4,b5,b6} misses {b7} holds
b1,b2,b3,b4,b5,b6,b7 are_mutually_different
proof end;

theorem Th9: :: BORSUK_5:9
for b1, b2, b3, b4, b5, b6, b7 being set st b1,b2,b3,b4,b5,b6,b7 are_mutually_different holds
b7,b1,b2,b3,b4,b5,b6 are_mutually_different
proof end;

theorem Th10: :: BORSUK_5:10
for b1, b2, b3, b4, b5, b6, b7 being set st b1,b2,b3,b4,b5,b6,b7 are_mutually_different holds
b1,b2,b5,b3,b6,b7,b4 are_mutually_different
proof end;

theorem Th11: :: BORSUK_5:11
for b1 being non empty TopSpace
for b2, b3 being Point of b1 st ex b4 being Function of I[01] ,b1 st
( b4 is continuous & b4 . 0 = b2 & b4 . 1 = b3 ) holds
ex b4 being Function of I[01] ,b1 st
( b4 is continuous & b4 . 0 = b3 & b4 . 1 = b2 )
proof end;

Lemma7: R^1 is arcwise_connected
proof end;

registration
cluster R^1 -> arcwise_connected ;
coherence
R^1 is arcwise_connected
by Lemma7;
end;

registration
cluster non empty connected TopStruct ;
existence
ex b1 being TopSpace st
( b1 is connected & not b1 is empty )
proof end;
end;

theorem Th12: :: BORSUK_5:12
canceled;

theorem Th13: :: BORSUK_5:13
[#] R^1 = REAL by PRE_TOPC:def 3, TOPMETR:24;

notation
let c1 be real number ;
synonym ].-infty,c1.] for left_closed_halfline c1;
synonym ].-infty,c1.[ for left_open_halfline c1;
synonym [.c1,+infty.[ for right_closed_halfline c1;
synonym ].c1,+infty.[ for right_open_halfline c1;
end;

theorem Th14: :: BORSUK_5:14
for b1, b2 being real number holds
( b1 in ].b2,+infty.[ iff b1 > b2 )
proof end;

theorem Th15: :: BORSUK_5:15
for b1, b2 being real number holds
( b1 in [.b2,+infty.[ iff b1 >= b2 )
proof end;

theorem Th16: :: BORSUK_5:16
for b1, b2 being real number holds
( b1 in ].-infty,b2.] iff b1 <= b2 )
proof end;

theorem Th17: :: BORSUK_5:17
for b1, b2 being real number holds
( b1 in ].-infty,b2.[ iff b1 < b2 )
proof end;

theorem Th18: :: BORSUK_5:18
for b1 being real number holds REAL \ {b1} = ].-infty,b1.[ \/ ].b1,+infty.[
proof end;

theorem Th19: :: BORSUK_5:19
for b1, b2, b3, b4 being real number st b1 < b2 & b2 <= b3 holds
[.b1,b2.] misses ].b3,b4.]
proof end;

theorem Th20: :: BORSUK_5:20
for b1, b2, b3, b4 being real number st b1 < b2 & b2 <= b3 holds
[.b1,b2.[ misses [.b3,b4.]
proof end;

theorem Th21: :: BORSUK_5:21
for b1, b2 being Subset of R^1
for b3, b4, b5, b6 being real number st b3 < b4 & b4 <= b5 & b5 < b6 & b1 = [.b3,b4.[ & b2 = ].b5,b6.] holds
b1,b2 are_separated
proof end;

Lemma16: for b1 being real number holds REAL \ ].-infty,b1.[ = [.b1,+infty.[
by LIMFUNC1:24;

Lemma17: for b1 being real number holds REAL \ ].-infty,b1.] = ].b1,+infty.[
by LIMFUNC1:24;

Lemma18: for b1 being real number holds REAL \ [.b1,+infty.[ = ].-infty,b1.[
by LIMFUNC1:24;

theorem Th22: :: BORSUK_5:22
canceled;

theorem Th23: :: BORSUK_5:23
canceled;

theorem Th24: :: BORSUK_5:24
canceled;

theorem Th25: :: BORSUK_5:25
canceled;

theorem Th26: :: BORSUK_5:26
for b1 being real number holds ].-infty,b1.] misses ].b1,+infty.[
proof end;

theorem Th27: :: BORSUK_5:27
for b1 being real number holds ].-infty,b1.[ misses [.b1,+infty.[
proof end;

theorem Th28: :: BORSUK_5:28
for b1, b2, b3 being real number st b1 <= b3 & b3 <= b2 holds
[.b1,b2.] \/ [.b3,+infty.[ = [.b1,+infty.[
proof end;

theorem Th29: :: BORSUK_5:29
for b1, b2, b3 being real number st b1 <= b3 & b3 <= b2 holds
].-infty,b3.] \/ [.b1,b2.] = ].-infty,b2.]
proof end;

registration
cluster -> real Element of RAT ;
coherence
for b1 being Element of RAT holds b1 is real
;
end;

registration
cluster -> real Element of the carrier of RealSpace ;
coherence
for b1 being Element of RealSpace holds b1 is real
by METRIC_1:def 14, XREAL_0:def 1;
end;

theorem Th30: :: BORSUK_5:30
canceled;

theorem Th31: :: BORSUK_5:31
canceled;

theorem Th32: :: BORSUK_5:32
canceled;

theorem Th33: :: BORSUK_5:33
for b1 being Subset of R^1
for b2 being Point of RealSpace holds
( b2 in Cl b1 iff for b3 being real number st b3 > 0 holds
Ball b2,b3 meets b1 ) by HAUSDORF:7, TOPMETR:def 7;

theorem Th34: :: BORSUK_5:34
for b1, b2 being Element of RealSpace st b2 >= b1 holds
dist b1,b2 = b2 - b1
proof end;

theorem Th35: :: BORSUK_5:35
for b1 being Subset of R^1 st b1 = RAT holds
Cl b1 = the carrier of R^1
proof end;

theorem Th36: :: BORSUK_5:36
for b1 being Subset of R^1
for b2, b3 being real number st b1 = ].b2,b3.[ & b2 <> b3 holds
Cl b1 = [.b2,b3.]
proof end;

registration
cluster number_e -> irrational ;
coherence
number_e is irrational
by IRRAT_1:42;
end;

definition
func IRRAT -> Subset of REAL equals :: BORSUK_5:def 3
REAL \ RAT ;
coherence
REAL \ RAT is Subset of REAL
by XBOOLE_1:36;
end;

:: deftheorem Def3 defines IRRAT BORSUK_5:def 3 :
IRRAT = REAL \ RAT ;

definition
let c1, c2 be real number ;
func RAT c1,c2 -> Subset of REAL equals :: BORSUK_5:def 4
RAT /\ ].a1,a2.[;
coherence
RAT /\ ].c1,c2.[ is Subset of REAL
proof end;
func IRRAT c1,c2 -> Subset of REAL equals :: BORSUK_5:def 5
IRRAT /\ ].a1,a2.[;
coherence
IRRAT /\ ].c1,c2.[ is Subset of REAL
;
end;

:: deftheorem Def4 defines RAT BORSUK_5:def 4 :
for b1, b2 being real number holds RAT b1,b2 = RAT /\ ].b1,b2.[;

:: deftheorem Def5 defines IRRAT BORSUK_5:def 5 :
for b1, b2 being real number holds IRRAT b1,b2 = IRRAT /\ ].b1,b2.[;

theorem Th37: :: BORSUK_5:37
for b1 being real number holds
( b1 is irrational iff b1 in IRRAT )
proof end;

registration
cluster real irrational set ;
existence
ex b1 being real number st b1 is irrational
by IRRAT_1:42;
end;

registration
cluster IRRAT -> non empty ;
coherence
not IRRAT is empty
by Th37, IRRAT_1:42;
end;

theorem Th38: :: BORSUK_5:38
for b1 being rational number
for b2 being real irrational number holds b1 + b2 is irrational
proof end;

theorem Th39: :: BORSUK_5:39
for b1 being real irrational number holds - b1 is irrational
proof end;

theorem Th40: :: BORSUK_5:40
for b1 being rational number
for b2 being real irrational number holds b1 - b2 is irrational
proof end;

theorem Th41: :: BORSUK_5:41
for b1 being rational number
for b2 being real irrational number holds b2 - b1 is irrational
proof end;

theorem Th42: :: BORSUK_5:42
for b1 being rational number
for b2 being real irrational number st b1 <> 0 holds
b1 * b2 is irrational
proof end;

theorem Th43: :: BORSUK_5:43
for b1 being rational number
for b2 being real irrational number st b1 <> 0 holds
b2 / b1 is irrational
proof end;

registration
cluster real irrational -> non zero real set ;
coherence
for b1 being real number st b1 is irrational holds
not b1 is empty
proof end;
end;

theorem Th44: :: BORSUK_5:44
for b1 being rational number
for b2 being real irrational number st b1 <> 0 holds
b1 / b2 is irrational
proof end;

theorem Th45: :: BORSUK_5:45
for b1 being real irrational number holds frac b1 is irrational
proof end;

registration
let c1 be real irrational number ;
cluster frac a1 -> non zero irrational ;
coherence
frac c1 is irrational
by Th45;
end;

registration
let c1 be real irrational number ;
cluster - a1 -> non zero irrational ;
coherence
- c1 is irrational
by Th39;
end;

registration
let c1 be rational number ;
let c2 be real irrational number ;
cluster a1 + a2 -> non zero irrational ;
coherence
c1 + c2 is irrational
by Th38;
cluster a2 + a1 -> non zero irrational ;
coherence
c2 + c1 is irrational
;
cluster a1 - a2 -> non zero irrational ;
coherence
c1 - c2 is irrational
by Th40;
cluster a2 - a1 -> non zero irrational ;
coherence
c2 - c1 is irrational
by Th41;
end;

registration
cluster non zero rational set ;
existence
not for b1 being rational number holds b1 is empty
proof end;
end;

registration
let c1 be non zero rational number ;
let c2 be real irrational number ;
cluster a1 * a2 -> non zero irrational ;
coherence
c1 * c2 is irrational
by Th42;
cluster a2 * a1 -> non zero irrational ;
coherence
c2 * c1 is irrational
;
cluster a1 / a2 -> non zero irrational ;
coherence
c1 / c2 is irrational
by Th44;
cluster a2 / a1 -> non zero irrational ;
coherence
c2 / c1 is irrational
by Th43;
end;

theorem Th46: :: BORSUK_5:46
canceled;

theorem Th47: :: BORSUK_5:47
for b1, b2 being real number st b1 < b2 holds
ex b3, b4 being rational number st
( b1 < b3 & b3 < b4 & b4 < b2 )
proof end;

Lemma36: for b1, b2, b3, b4 being real number st b1 <= b2 & b1 < b3 & 0 < b4 & b4 < 1 holds
b1 < ((1 - b4) * b2) + (b4 * b3)
by XREAL_1:179;

Lemma37: for b1, b2, b3, b4 being real number st b2 < b1 & b3 <= b1 & 0 < b4 & b4 < 1 holds
((1 - b4) * b2) + (b4 * b3) < b1
by XREAL_1:180;

theorem Th48: :: BORSUK_5:48
canceled;

theorem Th49: :: BORSUK_5:49
canceled;

theorem Th50: :: BORSUK_5:50
for b1, b2 being real number st b1 < b2 holds
ex b3 being real irrational number st
( b1 < b3 & b3 < b2 )
proof end;

theorem Th51: :: BORSUK_5:51
for b1 being Subset of R^1 st b1 = IRRAT holds
Cl b1 = the carrier of R^1
proof end;

Lemma40: for b1 being Subset of R^1
for b2, b3 being real number st b2 < b3 & b1 = RAT b2,b3 holds
( b2 in Cl b1 & b3 in Cl b1 )
proof end;

Lemma41: for b1 being Subset of R^1
for b2, b3 being real number st b2 < b3 & b1 = IRRAT b2,b3 holds
( b2 in Cl b1 & b3 in Cl b1 )
proof end;

theorem Th52: :: BORSUK_5:52
for b1, b2, b3 being real number st b1 < b2 holds
( b3 in RAT b1,b2 iff ( not b3 is irrational & b1 < b3 & b3 < b2 ) )
proof end;

theorem Th53: :: BORSUK_5:53
for b1, b2, b3 being real number st b1 < b2 holds
( b3 in IRRAT b1,b2 iff ( b3 is irrational & b1 < b3 & b3 < b2 ) )
proof end;

theorem Th54: :: BORSUK_5:54
for b1 being Subset of R^1
for b2, b3 being real number st b2 < b3 & b1 = RAT b2,b3 holds
Cl b1 = [.b2,b3.]
proof end;

theorem Th55: :: BORSUK_5:55
for b1 being Subset of R^1
for b2, b3 being real number st b2 < b3 & b1 = IRRAT b2,b3 holds
Cl b1 = [.b2,b3.]
proof end;

theorem Th56: :: BORSUK_5:56
for b1 being connected TopSpace
for b2 being open closed Subset of b1 holds
( b2 = {} or b2 = [#] b1 )
proof end;

theorem Th57: :: BORSUK_5:57
for b1 being Subset of R^1 st b1 is closed & b1 is open & not b1 = {} holds
b1 = REAL
proof end;

theorem Th58: :: BORSUK_5:58
for b1 being Subset of R^1
for b2, b3 being real number st b1 = [.b2,b3.[ & b2 <> b3 holds
Cl b1 = [.b2,b3.]
proof end;

theorem Th59: :: BORSUK_5:59
for b1 being Subset of R^1
for b2, b3 being real number st b1 = ].b2,b3.] & b2 <> b3 holds
Cl b1 = [.b2,b3.]
proof end;

theorem Th60: :: BORSUK_5:60
for b1 being Subset of R^1
for b2, b3, b4 being real number st b1 = [.b2,b3.[ \/ ].b3,b4.] & b2 < b3 & b3 < b4 holds
Cl b1 = [.b2,b4.]
proof end;

theorem Th61: :: BORSUK_5:61
for b1 being Subset of R^1
for b2 being real number st b1 = {b2} holds
Cl b1 = {b2}
proof end;

theorem Th62: :: BORSUK_5:62
for b1 being Subset of REAL
for b2 being Subset of R^1 st b1 = b2 holds
( b1 is open iff b2 is open )
proof end;

Lemma52: for b1 being real number holds ].b1,+infty.[ is open
by FCONT_3:7;

Lemma53: for b1 being real number holds ].-infty,b1.] is closed
by FCONT_3:6;

Lemma54: for b1 being real number holds ].-infty,b1.[ is open
by FCONT_3:8;

Lemma55: for b1 being real number holds [.b1,+infty.[ is closed
by FCONT_3:5;

theorem Th63: :: BORSUK_5:63
for b1 being Subset of R^1
for b2 being real number st b1 = ].b2,+infty.[ holds
b1 is open
proof end;

theorem Th64: :: BORSUK_5:64
for b1 being Subset of R^1
for b2 being real number st b1 = ].-infty,b2.[ holds
b1 is open
proof end;

theorem Th65: :: BORSUK_5:65
for b1 being Subset of R^1
for b2 being real number st b1 = ].-infty,b2.] holds
b1 is closed
proof end;

theorem Th66: :: BORSUK_5:66
for b1 being Subset of R^1
for b2 being real number st b1 = [.b2,+infty.[ holds
b1 is closed
proof end;

theorem Th67: :: BORSUK_5:67
for b1 being real number holds [.b1,+infty.[ = {b1} \/ ].b1,+infty.[
proof end;

theorem Th68: :: BORSUK_5:68
for b1 being real number holds ].-infty,b1.] = {b1} \/ ].-infty,b1.[
proof end;

Lemma62: for b1 being real number holds ].b1,+infty.[ c= [.b1,+infty.[
by LIMFUNC1:10;

Lemma63: for b1 being real number holds ].-infty,b1.[ c= ].-infty,b1.]
by LIMFUNC1:15;

registration
let c1 be real number ;
cluster ].a1,+infty.[ -> non empty ;
coherence
not ].c1,+infty.[ is empty
proof end;
cluster ].-infty,a1.] -> non empty ;
coherence
not ].-infty,c1.] is empty
by Th16;
cluster ].-infty,a1.[ -> non empty ;
coherence
not ].-infty,c1.[ is empty
proof end;
cluster [.a1,+infty.[ -> non empty ;
coherence
not [.c1,+infty.[ is empty
by Th15;
end;

theorem Th69: :: BORSUK_5:69
canceled;

theorem Th70: :: BORSUK_5:70
canceled;

theorem Th71: :: BORSUK_5:71
for b1 being real number holds ].b1,+infty.[ <> REAL
proof end;

theorem Th72: :: BORSUK_5:72
for b1 being real number holds [.b1,+infty.[ <> REAL
proof end;

theorem Th73: :: BORSUK_5:73
for b1 being real number holds ].-infty,b1.] <> REAL
proof end;

theorem Th74: :: BORSUK_5:74
for b1 being real number holds ].-infty,b1.[ <> REAL
proof end;

theorem Th75: :: BORSUK_5:75
for b1 being Subset of R^1
for b2 being real number st b1 = ].b2,+infty.[ holds
Cl b1 = [.b2,+infty.[
proof end;

theorem Th76: :: BORSUK_5:76
for b1 being real number holds Cl ].b1,+infty.[ = [.b1,+infty.[
proof end;

theorem Th77: :: BORSUK_5:77
for b1 being Subset of R^1
for b2 being real number st b1 = ].-infty,b2.[ holds
Cl b1 = ].-infty,b2.]
proof end;

theorem Th78: :: BORSUK_5:78
for b1 being real number holds Cl ].-infty,b1.[ = ].-infty,b1.]
proof end;

theorem Th79: :: BORSUK_5:79
for b1, b2 being Subset of R^1
for b3 being real number st b1 = ].-infty,b3.[ & b2 = ].b3,+infty.[ holds
b1,b2 are_separated
proof end;

theorem Th80: :: BORSUK_5:80
for b1 being Subset of R^1
for b2, b3 being real number st b2 < b3 & b1 = [.b2,b3.[ \/ ].b3,+infty.[ holds
Cl b1 = [.b2,+infty.[
proof end;

theorem Th81: :: BORSUK_5:81
for b1 being Subset of R^1
for b2, b3 being real number st b2 < b3 & b1 = ].b2,b3.[ \/ ].b3,+infty.[ holds
Cl b1 = [.b2,+infty.[
proof end;

theorem Th82: :: BORSUK_5:82
for b1 being Subset of R^1
for b2, b3, b4 being real number st b2 < b3 & b3 < b4 & b1 = ((RAT b2,b3) \/ ].b3,b4.[) \/ ].b4,+infty.[ holds
Cl b1 = [.b2,+infty.[
proof end;

theorem Th83: :: BORSUK_5:83
for b1 being Subset of R^1 holds b1 ` = REAL \ b1 by Th13, PRE_TOPC:17;

theorem Th84: :: BORSUK_5:84
for b1, b2 being real number st b1 < b2 holds
IRRAT b1,b2 misses RAT b1,b2
proof end;

Lemma71: for b1, b2 being real number st b2 <= b1 holds
RAT b1,b2 = {}
proof end;

Lemma72: for b1, b2 being real number st b2 <= b1 holds
REAL = ].-infty,b1.] \/ [.b2,+infty.[
proof end;

theorem Th85: :: BORSUK_5:85
for b1, b2 being real number holds REAL \ (RAT b1,b2) = (].-infty,b1.] \/ (IRRAT b1,b2)) \/ [.b2,+infty.[
proof end;

theorem Th86: :: BORSUK_5:86
for b1, b2, b3 being real number st b1 <= b2 & b2 < b3 holds
not b1 in ].b2,b3.[ \/ ].b3,+infty.[
proof end;

theorem Th87: :: BORSUK_5:87
for b1, b2 being real number st b1 < b2 holds
not b2 in ].b1,b2.[ \/ ].b2,+infty.[
proof end;

theorem Th88: :: BORSUK_5:88
for b1, b2 being real number st b1 < b2 holds
[.b1,+infty.[ \ (].b1,b2.[ \/ ].b2,+infty.[) = {b1} \/ {b2}
proof end;

theorem Th89: :: BORSUK_5:89
for b1 being Subset of R^1 st b1 = ((RAT 2,4) \/ ].4,5.[) \/ ].5,+infty.[ holds
b1 ` = ((].-infty,2.] \/ (IRRAT 2,4)) \/ {4}) \/ {5}
proof end;

theorem Th90: :: BORSUK_5:90
for b1 being Subset of R^1
for b2 being real number st b1 = {b2} holds
b1 ` = ].-infty,b2.[ \/ ].b2,+infty.[
proof end;

Lemma77: ((IRRAT 2,4) \/ {4}) \/ {5} c= ].1,+infty.[
proof end;

].1,+infty.[ c= [.1,+infty.[
by Lemma62;

then Lemma78: ((IRRAT 2,4) \/ {4}) \/ {5} c= [.1,+infty.[
by Lemma77, XBOOLE_1:1;

Lemma79: ].-infty,1.[ /\ (((].-infty,2.] \/ (IRRAT 2,4)) \/ {4}) \/ {5}) = ].-infty,1.[
proof end;

theorem Th91: :: BORSUK_5:91
for b1, b2 being real number st b1 < b2 holds
].b1,+infty.[ /\ ].-infty,b2.] = ].b1,b2.]
proof end;

Lemma81: ].1,+infty.[ /\ (((].-infty,2.] \/ (IRRAT 2,4)) \/ {4}) \/ {5}) = ((].1,2.] \/ (IRRAT 2,4)) \/ {4}) \/ {5}
proof end;

theorem Th92: :: BORSUK_5:92
(].-infty,1.[ \/ ].1,+infty.[) /\ (((].-infty,2.] \/ (IRRAT 2,4)) \/ {4}) \/ {5}) = (((].-infty,1.[ \/ ].1,2.]) \/ (IRRAT 2,4)) \/ {4}) \/ {5}
proof end;

theorem Th93: :: BORSUK_5:93
for b1, b2 being real number st b1 <= b2 holds
].-infty,b2.[ \ {b1} = ].-infty,b1.[ \/ ].b1,b2.[
proof end;

theorem Th94: :: BORSUK_5:94
for b1, b2 being real number st b1 <= b2 holds
].b1,+infty.[ \ {b2} = ].b1,b2.[ \/ ].b2,+infty.[
proof end;

theorem Th95: :: BORSUK_5:95
for b1 being Subset of R^1
for b2, b3 being real number st b2 <= b3 & b1 = {b2} \/ [.b3,+infty.[ holds
b1 ` = ].-infty,b2.[ \/ ].b2,b3.[
proof end;

theorem Th96: :: BORSUK_5:96
for b1 being Subset of R^1
for b2, b3 being real number st b2 < b3 & b1 = ].-infty,b2.[ \/ ].b2,b3.[ holds
Cl b1 = ].-infty,b3.]
proof end;

theorem Th97: :: BORSUK_5:97
for b1 being Subset of R^1
for b2, b3 being real number st b2 < b3 & b1 = ].-infty,b2.[ \/ ].b2,b3.] holds
Cl b1 = ].-infty,b3.]
proof end;

theorem Th98: :: BORSUK_5:98
for b1 being Subset of R^1
for b2 being real number st b1 = ].-infty,b2.] holds
b1 ` = ].b2,+infty.[
proof end;

theorem Th99: :: BORSUK_5:99
for b1 being Subset of R^1
for b2 being real number st b1 = [.b2,+infty.[ holds
b1 ` = ].-infty,b2.[
proof end;

theorem Th100: :: BORSUK_5:100
for b1 being Subset of R^1
for b2, b3, b4 being real number st b2 < b3 & b3 < b4 & b1 = ((].-infty,b2.[ \/ ].b2,b3.]) \/ (IRRAT b3,b4)) \/ {b4} holds
Cl b1 = ].-infty,b4.]
proof end;

theorem Th101: :: BORSUK_5:101
for b1 being Subset of R^1
for b2, b3, b4, b5 being real number st b2 < b3 & b3 < b4 & b1 = (((].-infty,b2.[ \/ ].b2,b3.]) \/ (IRRAT b3,b4)) \/ {b4}) \/ {b5} holds
Cl b1 = ].-infty,b4.] \/ {b5}
proof end;

theorem Th102: :: BORSUK_5:102
for b1 being Subset of R^1
for b2, b3 being real number st b2 <= b3 & b1 = ].-infty,b2.] \/ {b3} holds
b1 ` = ].b2,b3.[ \/ ].b3,+infty.[
proof end;

theorem Th103: :: BORSUK_5:103
for b1, b2 being real number holds [.b1,+infty.[ \/ {b2} <> REAL
proof end;

theorem Th104: :: BORSUK_5:104
for b1, b2 being real number holds ].-infty,b1.] \/ {b2} <> REAL
proof end;

theorem Th105: :: BORSUK_5:105
for b1 being TopStruct
for b2, b3 being Subset of b1 st b2 <> b3 holds
b2 ` <> b3 `
proof end;

theorem Th106: :: BORSUK_5:106
for b1 being Subset of R^1 st REAL = b1 ` holds
b1 = {}
proof end;

registration
cluster K384() -> arcwise_connected ;
coherence
I[01] is arcwise_connected
proof end;
end;

theorem Th107: :: BORSUK_5:107
for b1 being compact Subset of R^1
for b2 being Subset of REAL st b2 = b1 holds
( b2 is bounded_above & b2 is bounded_below )
proof end;

theorem Th108: :: BORSUK_5:108
for b1 being compact Subset of R^1
for b2 being Subset of REAL
for b3 being real number st b3 in b2 & b2 = b1 holds
( inf b2 <= b3 & b3 <= sup b2 )
proof end;

theorem Th109: :: BORSUK_5:109
for b1 being non empty connected compact Subset of R^1
for b2 being Subset of REAL st b1 = b2 & [.(inf b2),(sup b2).] c= b2 holds
[.(inf b2),(sup b2).] = b2
proof end;

theorem Th110: :: BORSUK_5:110
for b1 being connected Subset of R^1
for b2, b3, b4 being real number st b2 <= b3 & b3 <= b4 & b2 in b1 & b4 in b1 holds
b3 in b1
proof end;

theorem Th111: :: BORSUK_5:111
for b1 being connected Subset of R^1
for b2, b3 being real number st b2 in b1 & b3 in b1 holds
[.b2,b3.] c= b1
proof end;

theorem Th112: :: BORSUK_5:112
for b1 being non empty connected compact Subset of R^1 holds b1 is non empty closed-interval Subset of REAL
proof end;

theorem Th113: :: BORSUK_5:113
for b1 being non empty connected compact Subset of R^1 ex b2, b3 being real number st
( b2 <= b3 & b1 = [.b2,b3.] )
proof end;

definition
let c1 be TopStruct ;
let c2 be Subset-Family of c1;
attr a2 is with_proper_subsets means :Def6: :: BORSUK_5:def 6
not the carrier of a1 in a2;
end;

:: deftheorem Def6 defines with_proper_subsets BORSUK_5:def 6 :
for b1 being TopStruct
for b2 being Subset-Family of b1 holds
( b2 is with_proper_subsets iff not the carrier of b1 in b2 );

theorem Th114: :: BORSUK_5:114
for b1 being TopStruct
for b2, b3 being Subset-Family of b1 st b2 is with_proper_subsets & b3 c= b2 holds
b3 is with_proper_subsets
proof end;

registration
let c1 be non empty TopStruct ;
cluster with_proper_subsets Element of K22(K22(the carrier of a1));
existence
ex b1 being Subset-Family of c1 st b1 is with_proper_subsets
proof end;
end;

theorem Th115: :: BORSUK_5:115
for b1 being non empty TopStruct
for b2, b3 being with_proper_subsets Subset-Family of b1 holds b2 \/ b3 is with_proper_subsets
proof end;

registration
let c1 be TopSpace;
cluster non empty open closed Element of K22(K22(the carrier of a1));
existence
ex b1 being Subset-Family of c1 st
( b1 is open & b1 is closed & not b1 is empty )
proof end;
end;