:: RCOMP_2 semantic presentation

theorem Th1: :: RCOMP_2:1
canceled;

theorem Th2: :: RCOMP_2:2
for b1, b2, b3 being real number holds
( ( b1 < b2 & b3 < b2 ) iff max b1,b3 < b2 )
proof end;

definition
let c1, c2 be real number ;
func [.c1,c2.[ -> Subset of REAL equals :: RCOMP_2: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;
func ].c1,c2.] -> Subset of REAL equals :: RCOMP_2: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 Def1 defines [. RCOMP_2:def 1 :
for b1, b2 being real number holds [.b1,b2.[ = { b3 where B is Real : ( b1 <= b3 & b3 < b2 ) } ;

:: deftheorem Def2 defines ]. RCOMP_2:def 2 :
for b1, b2 being real number holds ].b1,b2.] = { b3 where B is Real : ( b1 < b3 & b3 <= b2 ) } ;

theorem Th3: :: RCOMP_2:3
for b1, b2, b3 being real number holds
( b1 in [.b2,b3.[ iff ( b2 <= b1 & b1 < b3 ) )
proof end;

theorem Th4: :: RCOMP_2:4
for b1, b2, b3 being real number holds
( b1 in ].b2,b3.] iff ( b2 < b1 & b1 <= b3 ) )
proof end;

theorem Th5: :: RCOMP_2:5
for b1, b2 being real number st b1 < b2 holds
[.b1,b2.[ = ].b1,b2.[ \/ {b1}
proof end;

theorem Th6: :: RCOMP_2:6
for b1, b2 being real number st b1 < b2 holds
].b1,b2.] = ].b1,b2.[ \/ {b2}
proof end;

theorem Th7: :: RCOMP_2:7
for b1 being real number holds [.b1,b1.[ = {}
proof end;

theorem Th8: :: RCOMP_2:8
for b1 being real number holds ].b1,b1.] = {}
proof end;

theorem Th9: :: RCOMP_2:9
for b1, b2 being real number st b1 <= b2 holds
[.b2,b1.[ = {}
proof end;

theorem Th10: :: RCOMP_2:10
for b1, b2 being real number st b1 <= b2 holds
].b2,b1.] = {}
proof end;

theorem Th11: :: RCOMP_2:11
for b1, b2, b3 being real number st b1 <= b2 & b2 <= b3 holds
[.b1,b2.[ \/ [.b2,b3.[ = [.b1,b3.[
proof end;

theorem Th12: :: RCOMP_2:12
for b1, b2, b3 being real number st b1 <= b2 & b2 <= b3 holds
].b1,b2.] \/ ].b2,b3.] = ].b1,b3.]
proof end;

theorem Th13: :: RCOMP_2:13
for b1, b2, b3, b4 being real number st b1 <= b2 & b1 <= b3 & b2 <= b4 & b3 <= b4 holds
[.b1,b4.] = ([.b1,b2.[ \/ [.b2,b3.]) \/ ].b3,b4.]
proof end;

theorem Th14: :: RCOMP_2:14
for b1, b2, b3, b4 being real number st b1 < b2 & b1 < b3 & b2 < b4 & b3 < b4 holds
].b1,b4.[ = (].b1,b2.] \/ ].b2,b3.[) \/ [.b3,b4.[
proof end;

theorem Th15: :: RCOMP_2:15
for b1, b2, b3, b4 being real number holds [.b1,b2.[ /\ [.b3,b4.[ = [.(max b1,b3),(min b2,b4).[
proof end;

theorem Th16: :: RCOMP_2:16
for b1, b2, b3, b4 being real number holds ].b1,b2.] /\ ].b3,b4.] = ].(max b1,b3),(min b2,b4).]
proof end;

theorem Th17: :: RCOMP_2:17
for b1, b2 being real number holds
( ].b1,b2.[ c= [.b1,b2.[ & ].b1,b2.[ c= ].b1,b2.] & [.b1,b2.[ c= [.b1,b2.] & ].b1,b2.] c= [.b1,b2.] )
proof end;

theorem Th18: :: RCOMP_2:18
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 Th19: :: RCOMP_2:19
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 Th20: :: RCOMP_2:20
for b1, b2, b3 being real number st b1 <= b2 & b2 <= b3 holds
[.b1,b2.] \/ ].b2,b3.] = [.b1,b3.]
proof end;

theorem Th21: :: RCOMP_2:21
for b1, b2, b3 being real number st b1 <= b2 & b2 <= b3 holds
[.b1,b2.[ \/ [.b2,b3.] = [.b1,b3.]
proof end;

theorem Th22: :: RCOMP_2:22
for b1, b2, b3, b4 being real number st [.b1,b2.[ meets [.b3,b4.[ holds
b2 >= b3
proof end;

theorem Th23: :: RCOMP_2:23
for b1, b2, b3, b4 being real number st ].b1,b2.] meets ].b3,b4.] holds
b2 >= b3
proof end;

theorem Th24: :: RCOMP_2:24
for b1, b2, b3, b4 being real number st [.b1,b2.[ meets [.b3,b4.[ holds
[.b1,b2.[ \/ [.b3,b4.[ = [.(min b1,b3),(max b2,b4).[
proof end;

theorem Th25: :: RCOMP_2:25
for b1, b2, b3, b4 being real number st ].b1,b2.] meets ].b3,b4.] holds
].b1,b2.] \/ ].b3,b4.] = ].(min b1,b3),(max b2,b4).]
proof end;

theorem Th26: :: RCOMP_2:26
for b1, b2, b3, b4 being real number st [.b1,b2.[ meets [.b3,b4.[ holds
[.b1,b2.[ \ [.b3,b4.[ = [.b1,b3.[ \/ [.b4,b2.[
proof end;

theorem Th27: :: RCOMP_2:27
for b1, b2, b3, b4 being real number st ].b1,b2.] meets ].b3,b4.] holds
].b1,b2.] \ ].b3,b4.] = ].b1,b3.] \/ ].b4,b2.]
proof end;