:: RCOMP_1 semantic presentation

scheme :: RCOMP_1:sch 1
s1{ P1[ set , set ] } :
ex b1 being Function of NAT , REAL st
for b2 being Nat holds P1[b2,b1 . b2]
provided
E1: for b1 being Nat ex b2 being real number st P1[b1,b2]
proof end;

theorem Th1: :: RCOMP_1:1
for b1, b2 being Subset of REAL st ( for b3 being real number st b3 in b1 holds
b3 in b2 ) holds
b1 c= b2
proof end;

theorem Th2: :: RCOMP_1:2
canceled;

theorem Th3: :: RCOMP_1:3
for b1, b2 being Subset of REAL st b1 c= b2 & b2 is bounded_below holds
b1 is bounded_below
proof end;

theorem Th4: :: RCOMP_1:4
for b1, b2 being Subset of REAL st b1 c= b2 & b2 is bounded_above holds
b1 is bounded_above
proof end;

theorem Th5: :: RCOMP_1:5
for b1, b2 being Subset of REAL st b1 c= b2 & b2 is bounded holds
b1 is bounded
proof end;

definition
let c1, c2 be real number ;
func [.c1,c2.] -> Subset of REAL equals :: RCOMP_1:def 1
{ b1 where B is Real : ( a1 <= b1 & b1 <= a2 ) } ;
coherence
{ b1 where B is Real : ( c1 <= b1 & b1 <= c2 ) } is Subset of REAL
proof end;
end;

:: deftheorem Def1 defines [. RCOMP_1:def 1 :
for b1, b2 being real number holds [.b1,b2.] = { b3 where B is Real : ( b1 <= b3 & b3 <= b2 ) } ;

definition
let c1, c2 be real number ;
func ].c1,c2.[ -> Subset of REAL equals :: RCOMP_1:def 2
{ b1 where B is Real : ( a1 < b1 & b1 < a2 ) } ;
coherence
{ b1 where B is Real : ( c1 < b1 & b1 < c2 ) } is Subset of REAL
proof end;
end;

:: deftheorem Def2 defines ]. RCOMP_1:def 2 :
for b1, b2 being real number holds ].b1,b2.[ = { b3 where B is Real : ( b1 < b3 & b3 < b2 ) } ;

theorem Th6: :: RCOMP_1:6
canceled;

theorem Th7: :: RCOMP_1:7
canceled;

theorem Th8: :: RCOMP_1:8
for b1, b2, b3 being real number holds
( b1 in ].(b2 - b3),(b2 + b3).[ iff abs (b1 - b2) < b3 )
proof end;

theorem Th9: :: RCOMP_1:9
for b1, b2, b3 being real number holds
( b1 in [.b2,b3.] iff abs ((b2 + b3) - (2 * b1)) <= b3 - b2 )
proof end;

theorem Th10: :: RCOMP_1:10
for b1, b2, b3 being real number holds
( b1 in ].b2,b3.[ iff abs ((b2 + b3) - (2 * b1)) < b3 - b2 )
proof end;

theorem Th11: :: RCOMP_1:11
for b1, b2 being real number st b1 <= b2 holds
[.b1,b2.] = ].b1,b2.[ \/ {b1,b2}
proof end;

theorem Th12: :: RCOMP_1:12
for b1, b2 being real number st b1 <= b2 holds
].b2,b1.[ = {}
proof end;

theorem Th13: :: RCOMP_1:13
for b1, b2 being real number st b1 < b2 holds
[.b2,b1.] = {}
proof end;

theorem Th14: :: RCOMP_1:14
for b1 being real number holds [.b1,b1.] = {b1}
proof end;

theorem Th15: :: RCOMP_1:15
for b1, b2 being real number holds
( ( b1 < b2 implies ].b1,b2.[ <> {} ) & ( b1 <= b2 implies ( b1 in [.b1,b2.] & b2 in [.b1,b2.] ) ) & ].b1,b2.[ c= [.b1,b2.] )
proof end;

theorem Th16: :: RCOMP_1:16
for b1, b2, b3, b4 being real number st b1 in [.b2,b3.] & b4 in [.b2,b3.] holds
[.b1,b4.] c= [.b2,b3.]
proof end;

theorem Th17: :: RCOMP_1:17
for b1, b2, b3, b4 being real number st b1 in ].b2,b3.[ & b4 in ].b2,b3.[ holds
[.b1,b4.] c= ].b2,b3.[
proof end;

theorem Th18: :: RCOMP_1:18
for b1, b2 being real number st b1 <= b2 holds
[.b1,b2.] = [.b1,b2.] \/ [.b2,b1.]
proof end;

definition
let c1 be Subset of REAL ;
attr a1 is compact means :Def3: :: RCOMP_1:def 3
for b1 being Real_Sequence st rng b1 c= a1 holds
ex b2 being Real_Sequence st
( b2 is subsequence of b1 & b2 is convergent & lim b2 in a1 );
end;

:: deftheorem Def3 defines compact RCOMP_1:def 3 :
for b1 being Subset of REAL holds
( b1 is compact iff for b2 being Real_Sequence st rng b2 c= b1 holds
ex b3 being Real_Sequence st
( b3 is subsequence of b2 & b3 is convergent & lim b3 in b1 ) );

definition
let c1 be Subset of REAL ;
attr a1 is closed means :Def4: :: RCOMP_1:def 4
for b1 being Real_Sequence st rng b1 c= a1 & b1 is convergent holds
lim b1 in a1;
end;

:: deftheorem Def4 defines closed RCOMP_1:def 4 :
for b1 being Subset of REAL holds
( b1 is closed iff for b2 being Real_Sequence st rng b2 c= b1 & b2 is convergent holds
lim b2 in b1 );

definition
let c1 be Subset of REAL ;
attr a1 is open means :Def5: :: RCOMP_1:def 5
a1 ` is closed;
end;

:: deftheorem Def5 defines open RCOMP_1:def 5 :
for b1 being Subset of REAL holds
( b1 is open iff b1 ` is closed );

theorem Th19: :: RCOMP_1:19
canceled;

theorem Th20: :: RCOMP_1:20
canceled;

theorem Th21: :: RCOMP_1:21
canceled;

theorem Th22: :: RCOMP_1:22
for b1, b2 being real number
for b3 being Real_Sequence st rng b3 c= [.b1,b2.] holds
b3 is bounded
proof end;

theorem Th23: :: RCOMP_1:23
for b1, b2 being real number holds [.b1,b2.] is closed
proof end;

theorem Th24: :: RCOMP_1:24
for b1, b2 being real number holds [.b1,b2.] is compact
proof end;

theorem Th25: :: RCOMP_1:25
for b1, b2 being real number holds ].b1,b2.[ is open
proof end;

registration
let c1, c2 be real number ;
cluster ].a1,a2.[ -> open ;
coherence
].c1,c2.[ is open
by Th25;
cluster [.a1,a2.] -> closed ;
coherence
[.c1,c2.] is closed
by Th23;
end;

theorem Th26: :: RCOMP_1:26
for b1 being Subset of REAL st b1 is compact holds
b1 is closed
proof end;

theorem Th27: :: RCOMP_1:27
for b1 being Real_Sequence
for b2 being Subset of REAL st ( for b3 being real number st b3 in b2 holds
ex b4 being real number ex b5 being Nat st
( 0 < b4 & ( for b6 being Nat st b5 < b6 holds
b4 < abs ((b1 . b6) - b3) ) ) ) holds
for b3 being Real_Sequence st b3 is subsequence of b1 & b3 is convergent holds
not lim b3 in b2
proof end;

theorem Th28: :: RCOMP_1:28
for b1 being Subset of REAL st b1 is compact holds
b1 is bounded
proof end;

theorem Th29: :: RCOMP_1:29
for b1 being Subset of REAL st b1 is bounded & b1 is closed holds
b1 is compact
proof end;

theorem Th30: :: RCOMP_1:30
for b1 being Subset of REAL st b1 <> {} & b1 is closed & b1 is bounded_above holds
upper_bound b1 in b1
proof end;

theorem Th31: :: RCOMP_1:31
for b1 being Subset of REAL st b1 <> {} & b1 is closed & b1 is bounded_below holds
lower_bound b1 in b1
proof end;

theorem Th32: :: RCOMP_1:32
for b1 being Subset of REAL st b1 <> {} & b1 is compact holds
( upper_bound b1 in b1 & lower_bound b1 in b1 )
proof end;

theorem Th33: :: RCOMP_1:33
for b1 being Subset of REAL st b1 is compact & ( for b2, b3 being real number st b2 in b1 & b3 in b1 holds
[.b2,b3.] c= b1 ) holds
ex b2, b3 being real number st b1 = [.b2,b3.]
proof end;

registration
cluster open Element of K40(REAL );
existence
ex b1 being Subset of REAL st b1 is open
proof end;
end;

definition
let c1 be real number ;
canceled;
mode Neighbourhood of c1 -> Subset of REAL means :Def7: :: RCOMP_1:def 7
ex b1 being real number st
( 0 < b1 & a2 = ].(a1 - b1),(a1 + b1).[ );
existence
ex b1 being Subset of REAL ex b2 being real number st
( 0 < b2 & b1 = ].(c1 - b2),(c1 + b2).[ )
proof end;
end;

:: deftheorem Def6 RCOMP_1:def 6 :
canceled;

:: deftheorem Def7 defines Neighbourhood RCOMP_1:def 7 :
for b1 being real number
for b2 being Subset of REAL holds
( b2 is Neighbourhood of b1 iff ex b3 being real number st
( 0 < b3 & b2 = ].(b1 - b3),(b1 + b3).[ ) );

registration
let c1 be real number ;
cluster -> open Neighbourhood of a1;
coherence
for b1 being Neighbourhood of c1 holds b1 is open
proof end;
end;

theorem Th34: :: RCOMP_1:34
canceled;

theorem Th35: :: RCOMP_1:35
canceled;

theorem Th36: :: RCOMP_1:36
canceled;

theorem Th37: :: RCOMP_1:37
for b1 being real number
for b2 being Neighbourhood of b1 holds b1 in b2
proof end;

theorem Th38: :: RCOMP_1:38
for b1 being real number
for b2, b3 being Neighbourhood of b1 ex b4 being Neighbourhood of b1 st
( b4 c= b2 & b4 c= b3 )
proof end;

theorem Th39: :: RCOMP_1:39
for b1 being open Subset of REAL
for b2 being real number st b2 in b1 holds
ex b3 being Neighbourhood of b2 st b3 c= b1
proof end;

theorem Th40: :: RCOMP_1:40
for b1 being open Subset of REAL
for b2 being real number st b2 in b1 holds
ex b3 being real number st
( 0 < b3 & ].(b2 - b3),(b2 + b3).[ c= b1 )
proof end;

theorem Th41: :: RCOMP_1:41
for b1 being Subset of REAL st ( for b2 being real number st b2 in b1 holds
ex b3 being Neighbourhood of b2 st b3 c= b1 ) holds
b1 is open
proof end;

theorem Th42: :: RCOMP_1:42
for b1 being Subset of REAL holds
( ( for b2 being real number st b2 in b1 holds
ex b3 being Neighbourhood of b2 st b3 c= b1 ) iff b1 is open ) by Th39, Th41;

theorem Th43: :: RCOMP_1:43
for b1 being Subset of REAL st b1 is open & b1 is bounded_above holds
not upper_bound b1 in b1
proof end;

theorem Th44: :: RCOMP_1:44
for b1 being Subset of REAL st b1 is open & b1 is bounded_below holds
not lower_bound b1 in b1
proof end;

theorem Th45: :: RCOMP_1:45
for b1 being Subset of REAL st b1 is open & b1 is bounded & ( for b2, b3 being real number st b2 in b1 & b3 in b1 holds
[.b2,b3.] c= b1 ) holds
ex b2, b3 being real number st b1 = ].b2,b3.[
proof end;

theorem Th46: :: RCOMP_1:46
for b1, b2 being real number holds ].b1,b2.[ misses {b1,b2}
proof end;

theorem Th47: :: RCOMP_1:47
for b1, b2, b3 being real number holds
( b3 in ].b1,b2.[ iff ( b1 < b3 & b3 < b2 ) )
proof end;

theorem Th48: :: RCOMP_1:48
for b1, b2, b3 being real number holds
( b3 in [.b1,b2.] iff ( b1 <= b3 & b3 <= b2 ) )
proof end;