:: SEQ_1 semantic presentation

definition
mode Real_Sequence is Function of NAT , REAL ;
end;

theorem Th1: :: SEQ_1:1
canceled;

theorem Th2: :: SEQ_1:2
canceled;

theorem Th3: :: SEQ_1:3
for b1 being Function holds
( b1 is Real_Sequence iff ( dom b1 = NAT & ( for b2 being set st b2 in NAT holds
b1 . b2 is real ) ) )
proof end;

theorem Th4: :: SEQ_1:4
for b1 being Function holds
( b1 is Real_Sequence iff ( dom b1 = NAT & ( for b2 being Nat holds b1 . b2 is real ) ) )
proof end;

definition
let c1 be Relation;
attr a1 is real-yielding means :Def1: :: SEQ_1:def 1
rng a1 c= REAL ;
end;

:: deftheorem Def1 defines real-yielding SEQ_1:def 1 :
for b1 being Relation holds
( b1 is real-yielding iff rng b1 c= REAL );

registration
let c1 be set ;
let c2 be real-membered set ;
cluster -> real-yielding Relation of a1,a2;
coherence
for b1 being PartFunc of c1,c2 holds b1 is real-yielding
proof end;
end;

registration
cluster real-yielding set ;
existence
ex b1 being Function st b1 is real-yielding
proof end;
end;

registration
let c1 be real-yielding Function;
let c2 be set ;
cluster a1 . a2 -> real ;
coherence
c1 . c2 is real
proof end;
end;

definition
let c1 be real-yielding Function;
let c2 be set ;
redefine func . as c1 . c2 -> Real;
coherence
c1 . c2 is Real
by XREAL_0:def 1;
end;

definition
let c1 be set ;
let c2 be real-membered set ;
let c3 be PartFunc of c1,c2;
let c4 be set ;
redefine func . as c3 . c4 -> Real;
coherence
c3 . c4 is Real
by XREAL_0:def 1;
end;

registration
let c1 be real-yielding Relation;
let c2 be set ;
cluster a1 | a2 -> real-yielding ;
coherence
c1 | c2 is real-yielding
proof end;
end;

notation
let c1 be PartFunc of NAT , REAL ;
synonym being_not_0 c1 for non-empty c1;
synonym c1 is_not_0 for non-empty c1;
end;

definition
let c1 be PartFunc of NAT , REAL ;
redefine attr a1 is non-empty means :Def2: :: SEQ_1:def 2
rng a1 c= REAL \ {0};
compatibility
( c1 is being_not_0 iff rng c1 c= REAL \ {0} )
proof end;
end;

:: deftheorem Def2 defines being_not_0 SEQ_1:def 2 :
for b1 being PartFunc of NAT , REAL holds
( b1 is being_not_0 iff rng b1 c= REAL \ {0} );

theorem Th5: :: SEQ_1:5
canceled;

theorem Th6: :: SEQ_1:6
for b1 being Real_Sequence holds
( b1 is being_not_0 iff for b2 being set st b2 in NAT holds
b1 . b2 <> 0 )
proof end;

theorem Th7: :: SEQ_1:7
for b1 being Real_Sequence holds
( b1 is being_not_0 iff for b2 being Nat holds b1 . b2 <> 0 )
proof end;

theorem Th8: :: SEQ_1:8
for b1, b2 being Real_Sequence st ( for b3 being set st b3 in NAT holds
b1 . b3 = b2 . b3 ) holds
b1 = b2
proof end;

theorem Th9: :: SEQ_1:9
canceled;

theorem Th10: :: SEQ_1:10
for b1 being real number ex b2 being Real_Sequence st rng b2 = {b1}
proof end;

scheme :: SEQ_1:sch 1
s1{ F1( set ) -> real number } :
ex b1 being Real_Sequence st
for b2 being Nat holds b1 . b2 = F1(b2)
proof end;

scheme :: SEQ_1:sch 2
s2{ F1() -> non empty set , F2() -> non empty set , P1[ set , set ] } :
ex b1 being PartFunc of F1(),F2() st
( ( for b2 being Element of F1() holds
( b2 in dom b1 iff ex b3 being Element of F2() st P1[b2,b3] ) ) & ( for b2 being Element of F1() st b2 in dom b1 holds
P1[b2,b1 . b2] ) )
proof end;

scheme :: SEQ_1:sch 3
s3{ F1() -> non empty set , F2() -> non empty set , F3( set ) -> Element of F2(), P1[ set ] } :
ex b1 being PartFunc of F1(),F2() st
( ( for b2 being Element of F1() holds
( b2 in dom b1 iff P1[b2] ) ) & ( for b2 being Element of F1() st b2 in dom b1 holds
b1 . b2 = F3(b2) ) )
proof end;

scheme :: SEQ_1:sch 4
s4{ F1() -> set , F2() -> set , F3() -> set , F4( set ) -> set } :
for b1, b2 being PartFunc of F1(),F2() st dom b1 = F3() & ( for b3 being Element of F1() st b3 in dom b1 holds
b1 . b3 = F4(b3) ) & dom b2 = F3() & ( for b3 being Element of F1() st b3 in dom b2 holds
b2 . b3 = F4(b3) ) holds
b1 = b2
proof end;

definition
let c1, c2 be real-yielding Function;
func c1 + c2 -> Function means :Def3: :: SEQ_1:def 3
( dom a3 = (dom a1) /\ (dom a2) & ( for b1 being set st b1 in dom a3 holds
a3 . b1 = (a1 . b1) + (a2 . b1) ) );
existence
ex b1 being Function st
( dom b1 = (dom c1) /\ (dom c2) & ( for b2 being set st b2 in dom b1 holds
b1 . b2 = (c1 . b2) + (c2 . b2) ) )
proof end;
uniqueness
for b1, b2 being Function st dom b1 = (dom c1) /\ (dom c2) & ( for b3 being set st b3 in dom b1 holds
b1 . b3 = (c1 . b3) + (c2 . b3) ) & dom b2 = (dom c1) /\ (dom c2) & ( for b3 being set st b3 in dom b2 holds
b2 . b3 = (c1 . b3) + (c2 . b3) ) holds
b1 = b2
proof end;
commutativity
for b1 being Function
for b2, b3 being real-yielding Function st dom b1 = (dom b2) /\ (dom b3) & ( for b4 being set st b4 in dom b1 holds
b1 . b4 = (b2 . b4) + (b3 . b4) ) holds
( dom b1 = (dom b3) /\ (dom b2) & ( for b4 being set st b4 in dom b1 holds
b1 . b4 = (b3 . b4) + (b2 . b4) ) )
;
func c1 - c2 -> Function means :Def4: :: SEQ_1:def 4
( dom a3 = (dom a1) /\ (dom a2) & ( for b1 being set st b1 in dom a3 holds
a3 . b1 = (a1 . b1) - (a2 . b1) ) );
existence
ex b1 being Function st
( dom b1 = (dom c1) /\ (dom c2) & ( for b2 being set st b2 in dom b1 holds
b1 . b2 = (c1 . b2) - (c2 . b2) ) )
proof end;
uniqueness
for b1, b2 being Function st dom b1 = (dom c1) /\ (dom c2) & ( for b3 being set st b3 in dom b1 holds
b1 . b3 = (c1 . b3) - (c2 . b3) ) & dom b2 = (dom c1) /\ (dom c2) & ( for b3 being set st b3 in dom b2 holds
b2 . b3 = (c1 . b3) - (c2 . b3) ) holds
b1 = b2
proof end;
func c1 (#) c2 -> Function means :Def5: :: SEQ_1:def 5
( dom a3 = (dom a1) /\ (dom a2) & ( for b1 being set st b1 in dom a3 holds
a3 . b1 = (a1 . b1) * (a2 . b1) ) );
existence
ex b1 being Function st
( dom b1 = (dom c1) /\ (dom c2) & ( for b2 being set st b2 in dom b1 holds
b1 . b2 = (c1 . b2) * (c2 . b2) ) )
proof end;
uniqueness
for b1, b2 being Function st dom b1 = (dom c1) /\ (dom c2) & ( for b3 being set st b3 in dom b1 holds
b1 . b3 = (c1 . b3) * (c2 . b3) ) & dom b2 = (dom c1) /\ (dom c2) & ( for b3 being set st b3 in dom b2 holds
b2 . b3 = (c1 . b3) * (c2 . b3) ) holds
b1 = b2
proof end;
commutativity
for b1 being Function
for b2, b3 being real-yielding Function st dom b1 = (dom b2) /\ (dom b3) & ( for b4 being set st b4 in dom b1 holds
b1 . b4 = (b2 . b4) * (b3 . b4) ) holds
( dom b1 = (dom b3) /\ (dom b2) & ( for b4 being set st b4 in dom b1 holds
b1 . b4 = (b3 . b4) * (b2 . b4) ) )
;
end;

:: deftheorem Def3 defines + SEQ_1:def 3 :
for b1, b2 being real-yielding Function
for b3 being Function holds
( b3 = b1 + b2 iff ( dom b3 = (dom b1) /\ (dom b2) & ( for b4 being set st b4 in dom b3 holds
b3 . b4 = (b1 . b4) + (b2 . b4) ) ) );

:: deftheorem Def4 defines - SEQ_1:def 4 :
for b1, b2 being real-yielding Function
for b3 being Function holds
( b3 = b1 - b2 iff ( dom b3 = (dom b1) /\ (dom b2) & ( for b4 being set st b4 in dom b3 holds
b3 . b4 = (b1 . b4) - (b2 . b4) ) ) );

:: deftheorem Def5 defines (#) SEQ_1:def 5 :
for b1, b2 being real-yielding Function
for b3 being Function holds
( b3 = b1 (#) b2 iff ( dom b3 = (dom b1) /\ (dom b2) & ( for b4 being set st b4 in dom b3 holds
b3 . b4 = (b1 . b4) * (b2 . b4) ) ) );

registration
let c1, c2 be real-yielding Function;
cluster a1 + a2 -> real-yielding ;
coherence
c1 + c2 is real-yielding
proof end;
cluster a1 - a2 -> real-yielding ;
coherence
c1 - c2 is real-yielding
proof end;
cluster a1 (#) a2 -> real-yielding ;
coherence
c1 (#) c2 is real-yielding
proof end;
end;

definition
let c1 be set ;
let c2 be real-membered set ;
let c3, c4 be PartFunc of c1,c2;
redefine func + as c3 + c4 -> PartFunc of a1, REAL ;
coherence
c3 + c4 is PartFunc of c1, REAL
proof end;
redefine func - as c3 - c4 -> PartFunc of a1, REAL ;
coherence
c3 - c4 is PartFunc of c1, REAL
proof end;
redefine func (#) as c3 (#) c4 -> PartFunc of a1, REAL ;
coherence
c3 (#) c4 is PartFunc of c1, REAL
proof end;
end;

theorem Th11: :: SEQ_1:11
for b1, b2, b3 being Real_Sequence holds
( b1 = b2 + b3 iff for b4 being Nat holds b1 . b4 = (b2 . b4) + (b3 . b4) )
proof end;

theorem Th12: :: SEQ_1:12
for b1, b2, b3 being Real_Sequence holds
( b1 = b2 (#) b3 iff for b4 being Nat holds b1 . b4 = (b2 . b4) * (b3 . b4) )
proof end;

definition
let c1, c2 be Real_Sequence;
redefine func + as c1 + c2 -> Real_Sequence;
coherence
c1 + c2 is Real_Sequence
proof end;
redefine func - as c1 - c2 -> Real_Sequence;
coherence
c1 - c2 is Real_Sequence
proof end;
redefine func (#) as c1 (#) c2 -> Real_Sequence;
coherence
c1 (#) c2 is Real_Sequence
proof end;
end;

definition
let c1 be real-yielding Function;
let c2 be real number ;
func c2 (#) c1 -> Function means :Def6: :: SEQ_1:def 6
( dom a3 = dom a1 & ( for b1 being set st b1 in dom a3 holds
a3 . b1 = a2 * (a1 . b1) ) );
existence
ex b1 being Function st
( dom b1 = dom c1 & ( for b2 being set st b2 in dom b1 holds
b1 . b2 = c2 * (c1 . b2) ) )
proof end;
uniqueness
for b1, b2 being Function st dom b1 = dom c1 & ( for b3 being set st b3 in dom b1 holds
b1 . b3 = c2 * (c1 . b3) ) & dom b2 = dom c1 & ( for b3 being set st b3 in dom b2 holds
b2 . b3 = c2 * (c1 . b3) ) holds
b1 = b2
proof end;
end;

:: deftheorem Def6 defines (#) SEQ_1:def 6 :
for b1 being real-yielding Function
for b2 being real number
for b3 being Function holds
( b3 = b2 (#) b1 iff ( dom b3 = dom b1 & ( for b4 being set st b4 in dom b3 holds
b3 . b4 = b2 * (b1 . b4) ) ) );

registration
let c1 be real number ;
let c2 be real-yielding Function;
cluster a1 (#) a2 -> real-yielding ;
coherence
c1 (#) c2 is real-yielding
proof end;
end;

definition
let c1 be set ;
let c2 be real-membered set ;
let c3 be PartFunc of c1,c2;
let c4 be real number ;
redefine func (#) as c4 (#) c3 -> PartFunc of a1, REAL ;
coherence
c4 (#) c3 is PartFunc of c1, REAL
proof end;
end;

definition
let c1 be Real_Sequence;
let c2 be real number ;
redefine func (#) as c2 (#) c1 -> Real_Sequence;
coherence
c2 (#) c1 is Real_Sequence
proof end;
end;

theorem Th13: :: SEQ_1:13
for b1 being real number
for b2, b3 being Real_Sequence holds
( b2 = b1 (#) b3 iff for b4 being Nat holds b2 . b4 = b1 * (b3 . b4) )
proof end;

definition
let c1 be real-yielding Function;
func - c1 -> Function means :Def7: :: SEQ_1:def 7
( dom a2 = dom a1 & ( for b1 being set st b1 in dom a2 holds
a2 . b1 = - (a1 . b1) ) );
existence
ex b1 being Function st
( dom b1 = dom c1 & ( for b2 being set st b2 in dom b1 holds
b1 . b2 = - (c1 . b2) ) )
proof end;
uniqueness
for b1, b2 being Function st dom b1 = dom c1 & ( for b3 being set st b3 in dom b1 holds
b1 . b3 = - (c1 . b3) ) & dom b2 = dom c1 & ( for b3 being set st b3 in dom b2 holds
b2 . b3 = - (c1 . b3) ) holds
b1 = b2
proof end;
end;

:: deftheorem Def7 defines - SEQ_1:def 7 :
for b1 being real-yielding Function
for b2 being Function holds
( b2 = - b1 iff ( dom b2 = dom b1 & ( for b3 being set st b3 in dom b2 holds
b2 . b3 = - (b1 . b3) ) ) );

registration
let c1 be real-yielding Function;
cluster - a1 -> real-yielding ;
coherence
- c1 is real-yielding
proof end;
end;

definition
let c1 be set ;
let c2 be real-membered set ;
let c3 be PartFunc of c1,c2;
redefine func - as - c3 -> PartFunc of a1, REAL ;
coherence
- c3 is PartFunc of c1, REAL
proof end;
end;

definition
let c1 be Real_Sequence;
redefine func - as - c1 -> Real_Sequence;
coherence
- c1 is Real_Sequence
proof end;
end;

theorem Th14: :: SEQ_1:14
for b1, b2 being Real_Sequence holds
( b1 = - b2 iff for b3 being Nat holds b1 . b3 = - (b2 . b3) )
proof end;

theorem Th15: :: SEQ_1:15
for b1, b2 being Real_Sequence holds b1 - b2 = b1 + (- b2)
proof end;

definition
let c1 be Real_Sequence;
func c1 " -> Real_Sequence means :Def8: :: SEQ_1:def 8
for b1 being Nat holds a2 . b1 = (a1 . b1) " ;
existence
ex b1 being Real_Sequence st
for b2 being Nat holds b1 . b2 = (c1 . b2) "
proof end;
uniqueness
for b1, b2 being Real_Sequence st ( for b3 being Nat holds b1 . b3 = (c1 . b3) " ) & ( for b3 being Nat holds b2 . b3 = (c1 . b3) " ) holds
b1 = b2
proof end;
end;

:: deftheorem Def8 defines " SEQ_1:def 8 :
for b1 being Real_Sequence
for b2 being Real_Sequence holds
( b2 = b1 " iff for b3 being Nat holds b2 . b3 = (b1 . b3) " );

definition
let c1, c2 be Real_Sequence;
func c1 /" c2 -> Real_Sequence equals :: SEQ_1:def 9
a1 (#) (a2 " );
correctness
coherence
c1 (#) (c2 " ) is Real_Sequence
;
;
end;

:: deftheorem Def9 defines /" SEQ_1:def 9 :
for b1, b2 being Real_Sequence holds b1 /" b2 = b1 (#) (b2 " );

definition
let c1 be real-yielding Function;
func abs c1 -> Function means :Def10: :: SEQ_1:def 10
( dom a2 = dom a1 & ( for b1 being set st b1 in dom a2 holds
a2 . b1 = abs (a1 . b1) ) );
existence
ex b1 being Function st
( dom b1 = dom c1 & ( for b2 being set st b2 in dom b1 holds
b1 . b2 = abs (c1 . b2) ) )
proof end;
uniqueness
for b1, b2 being Function st dom b1 = dom c1 & ( for b3 being set st b3 in dom b1 holds
b1 . b3 = abs (c1 . b3) ) & dom b2 = dom c1 & ( for b3 being set st b3 in dom b2 holds
b2 . b3 = abs (c1 . b3) ) holds
b1 = b2
proof end;
end;

:: deftheorem Def10 defines abs SEQ_1:def 10 :
for b1 being real-yielding Function
for b2 being Function holds
( b2 = abs b1 iff ( dom b2 = dom b1 & ( for b3 being set st b3 in dom b2 holds
b2 . b3 = abs (b1 . b3) ) ) );

registration
let c1 be real-yielding Function;
cluster abs a1 -> real-yielding ;
coherence
abs c1 is real-yielding
proof end;
end;

definition
let c1 be set ;
let c2 be real-membered set ;
let c3 be PartFunc of c1,c2;
redefine func abs as abs c3 -> PartFunc of a1, REAL ;
coherence
abs c3 is PartFunc of c1, REAL
proof end;
end;

definition
let c1 be Real_Sequence;
redefine func abs as abs c1 -> Real_Sequence;
coherence
abs c1 is Real_Sequence
proof end;
end;

theorem Th16: :: SEQ_1:16
for b1, b2 being Real_Sequence holds
( b1 = abs b2 iff for b3 being Nat holds b1 . b3 = abs (b2 . b3) )
proof end;

theorem Th17: :: SEQ_1:17
canceled;

theorem Th18: :: SEQ_1:18
canceled;

theorem Th19: :: SEQ_1:19
canceled;

theorem Th20: :: SEQ_1:20
for b1, b2, b3 being Real_Sequence holds (b1 + b2) + b3 = b1 + (b2 + b3)
proof end;

theorem Th21: :: SEQ_1:21
canceled;

theorem Th22: :: SEQ_1:22
for b1, b2, b3 being Real_Sequence holds (b1 (#) b2) (#) b3 = b1 (#) (b2 (#) b3)
proof end;

theorem Th23: :: SEQ_1:23
for b1, b2, b3 being Real_Sequence holds (b1 + b2) (#) b3 = (b1 (#) b3) + (b2 (#) b3)
proof end;

theorem Th24: :: SEQ_1:24
for b1, b2, b3 being Real_Sequence holds b1 (#) (b2 + b3) = (b1 (#) b2) + (b1 (#) b3) by Th23;

theorem Th25: :: SEQ_1:25
for b1 being Real_Sequence holds - b1 = (- 1) (#) b1
proof end;

theorem Th26: :: SEQ_1:26
for b1 being real number
for b2, b3 being Real_Sequence holds b1 (#) (b2 (#) b3) = (b1 (#) b2) (#) b3
proof end;

theorem Th27: :: SEQ_1:27
for b1 being real number
for b2, b3 being Real_Sequence holds b1 (#) (b2 (#) b3) = b2 (#) (b1 (#) b3)
proof end;

theorem Th28: :: SEQ_1:28
for b1, b2, b3 being Real_Sequence holds (b1 - b2) (#) b3 = (b1 (#) b3) - (b2 (#) b3)
proof end;

theorem Th29: :: SEQ_1:29
for b1, b2, b3 being Real_Sequence holds (b1 (#) b2) - (b1 (#) b3) = b1 (#) (b2 - b3) by Th28;

theorem Th30: :: SEQ_1:30
for b1 being real number
for b2, b3 being Real_Sequence holds b1 (#) (b2 + b3) = (b1 (#) b2) + (b1 (#) b3)
proof end;

theorem Th31: :: SEQ_1:31
for b1, b2 being real number
for b3 being Real_Sequence holds (b1 * b2) (#) b3 = b1 (#) (b2 (#) b3)
proof end;

theorem Th32: :: SEQ_1:32
for b1 being real number
for b2, b3 being Real_Sequence holds b1 (#) (b2 - b3) = (b1 (#) b2) - (b1 (#) b3)
proof end;

theorem Th33: :: SEQ_1:33
for b1 being real number
for b2, b3 being Real_Sequence holds b1 (#) (b2 /" b3) = (b1 (#) b2) /" b3 by Th26;

theorem Th34: :: SEQ_1:34
for b1, b2, b3 being Real_Sequence holds b1 - (b2 + b3) = (b1 - b2) - b3
proof end;

theorem Th35: :: SEQ_1:35
for b1 being Real_Sequence holds 1 (#) b1 = b1
proof end;

theorem Th36: :: SEQ_1:36
for b1 being Real_Sequence holds - (- b1) = b1
proof end;

theorem Th37: :: SEQ_1:37
for b1, b2 being Real_Sequence holds b1 - (- b2) = b1 + b2
proof end;

theorem Th38: :: SEQ_1:38
for b1, b2, b3 being Real_Sequence holds b1 - (b2 - b3) = (b1 - b2) + b3
proof end;

theorem Th39: :: SEQ_1:39
for b1, b2, b3 being Real_Sequence holds b1 + (b2 - b3) = (b1 + b2) - b3
proof end;

theorem Th40: :: SEQ_1:40
for b1, b2 being Real_Sequence holds
( (- b1) (#) b2 = - (b1 (#) b2) & b1 (#) (- b2) = - (b1 (#) b2) )
proof end;

theorem Th41: :: SEQ_1:41
for b1 being Real_Sequence st b1 is being_not_0 holds
b1 " is being_not_0
proof end;

theorem Th42: :: SEQ_1:42
for b1 being Real_Sequence holds (b1 " ) " = b1
proof end;

theorem Th43: :: SEQ_1:43
for b1, b2 being Real_Sequence holds
( ( b1 is being_not_0 & b2 is being_not_0 ) iff b1 (#) b2 is being_not_0 )
proof end;

theorem Th44: :: SEQ_1:44
for b1, b2 being Real_Sequence holds (b1 " ) (#) (b2 " ) = (b1 (#) b2) "
proof end;

theorem Th45: :: SEQ_1:45
for b1, b2 being Real_Sequence st b1 is being_not_0 holds
(b2 /" b1) (#) b1 = b2
proof end;

theorem Th46: :: SEQ_1:46
for b1, b2, b3, b4 being Real_Sequence holds (b1 /" b2) (#) (b3 /" b4) = (b1 (#) b3) /" (b2 (#) b4)
proof end;

theorem Th47: :: SEQ_1:47
for b1, b2 being Real_Sequence st b1 is being_not_0 & b2 is being_not_0 holds
b1 /" b2 is being_not_0
proof end;

theorem Th48: :: SEQ_1:48
for b1, b2 being Real_Sequence holds (b1 /" b2) " = b2 /" b1
proof end;

theorem Th49: :: SEQ_1:49
for b1, b2, b3 being Real_Sequence holds b1 (#) (b2 /" b3) = (b1 (#) b2) /" b3 by Th22;

theorem Th50: :: SEQ_1:50
for b1, b2, b3 being Real_Sequence holds b1 /" (b2 /" b3) = (b1 (#) b3) /" b2
proof end;

theorem Th51: :: SEQ_1:51
for b1, b2, b3 being Real_Sequence st b1 is being_not_0 holds
b2 /" b3 = (b2 (#) b1) /" (b3 (#) b1)
proof end;

theorem Th52: :: SEQ_1:52
for b1 being real number
for b2 being Real_Sequence st b1 <> 0 & b2 is being_not_0 holds
b1 (#) b2 is being_not_0
proof end;

theorem Th53: :: SEQ_1:53
for b1 being Real_Sequence st b1 is being_not_0 holds
- b1 is being_not_0
proof end;

theorem Th54: :: SEQ_1:54
for b1 being real number
for b2 being Real_Sequence holds (b1 (#) b2) " = (b1 " ) (#) (b2 " )
proof end;

Lemma43: (- 1) " = - 1
;

theorem Th55: :: SEQ_1:55
for b1 being Real_Sequence holds (- b1) " = (- 1) (#) (b1 " )
proof end;

theorem Th56: :: SEQ_1:56
for b1, b2 being Real_Sequence holds
( - (b1 /" b2) = (- b1) /" b2 & b1 /" (- b2) = - (b1 /" b2) )
proof end;

theorem Th57: :: SEQ_1:57
for b1, b2, b3 being Real_Sequence holds
( (b1 /" b2) + (b3 /" b2) = (b1 + b3) /" b2 & (b1 /" b2) - (b3 /" b2) = (b1 - b3) /" b2 ) by Th23, Th28;

theorem Th58: :: SEQ_1:58
for b1, b2, b3, b4 being Real_Sequence st b1 is being_not_0 & b2 is being_not_0 holds
( (b3 /" b1) + (b4 /" b2) = ((b3 (#) b2) + (b4 (#) b1)) /" (b1 (#) b2) & (b3 /" b1) - (b4 /" b2) = ((b3 (#) b2) - (b4 (#) b1)) /" (b1 (#) b2) )
proof end;

theorem Th59: :: SEQ_1:59
for b1, b2, b3, b4 being Real_Sequence holds (b1 /" b2) /" (b3 /" b4) = (b1 (#) b4) /" (b2 (#) b3)
proof end;

theorem Th60: :: SEQ_1:60
for b1, b2 being Real_Sequence holds abs (b1 (#) b2) = (abs b1) (#) (abs b2)
proof end;

theorem Th61: :: SEQ_1:61
for b1 being Real_Sequence st b1 is being_not_0 holds
abs b1 is being_not_0
proof end;

theorem Th62: :: SEQ_1:62
for b1 being Real_Sequence holds (abs b1) " = abs (b1 " )
proof end;

theorem Th63: :: SEQ_1:63
for b1, b2 being Real_Sequence holds abs (b1 /" b2) = (abs b1) /" (abs b2)
proof end;

theorem Th64: :: SEQ_1:64
for b1 being real number
for b2 being Real_Sequence holds abs (b1 (#) b2) = (abs b1) (#) (abs b2)
proof end;