:: TOPREAL9 semantic presentation

theorem Th1: :: TOPREAL9:1
for b1 being Nat
for b2, b3, b4 being Point of (TOP-REAL b1) holds (b2 - b3) - b4 = (b2 - b4) - b3
proof end;

theorem Th2: :: TOPREAL9:2
for b1 being Nat
for b2, b3, b4 being Point of (TOP-REAL b1) st b2 + b3 = b2 + b4 holds
b3 = b4
proof end;

theorem Th3: :: TOPREAL9:3
for b1 being Nat
for b2 being Point of (TOP-REAL b1) st not b1 is empty holds
b2 <> b2 + (1.REAL b1)
proof end;

theorem Th4: :: TOPREAL9:4
for b1 being Nat
for b2 being real number
for b3, b4 being Point of (TOP-REAL b1)
for b5 being set st b5 = ((1 - b2) * b3) + (b2 * b4) holds
( ( not b5 = b3 or b2 = 0 or b3 = b4 ) & ( ( b2 = 0 or b3 = b4 ) implies b5 = b3 ) & ( not b5 = b4 or b2 = 1 or b3 = b4 ) & ( ( b2 = 1 or b3 = b4 ) implies b5 = b4 ) )
proof end;

theorem Th5: :: TOPREAL9:5
for b1 being FinSequence of REAL holds |.b1.| ^2 = Sum (sqr b1)
proof end;

theorem Th6: :: TOPREAL9:6
for b1 being real number
for b2 being non empty MetrSpace
for b3, b4, b5 being Point of b2 st b3 <> b4 & b3 in cl_Ball b5,b1 & b4 in cl_Ball b5,b1 holds
b1 > 0
proof end;

definition
let c1 be Nat;
let c2 be Point of (TOP-REAL c1);
let c3 be real number ;
func Ball c2,c3 -> Subset of (TOP-REAL a1) equals :: TOPREAL9:def 1
{ b1 where B is Point of (TOP-REAL a1) : |.(b1 - a2).| < a3 } ;
coherence
{ b1 where B is Point of (TOP-REAL c1) : |.(b1 - c2).| < c3 } is Subset of (TOP-REAL c1)
proof end;
func cl_Ball c2,c3 -> Subset of (TOP-REAL a1) equals :: TOPREAL9:def 2
{ b1 where B is Point of (TOP-REAL a1) : |.(b1 - a2).| <= a3 } ;
coherence
{ b1 where B is Point of (TOP-REAL c1) : |.(b1 - c2).| <= c3 } is Subset of (TOP-REAL c1)
proof end;
func Sphere c2,c3 -> Subset of (TOP-REAL a1) equals :: TOPREAL9:def 3
{ b1 where B is Point of (TOP-REAL a1) : |.(b1 - a2).| = a3 } ;
coherence
{ b1 where B is Point of (TOP-REAL c1) : |.(b1 - c2).| = c3 } is Subset of (TOP-REAL c1)
proof end;
end;

:: deftheorem Def1 defines Ball TOPREAL9:def 1 :
for b1 being Nat
for b2 being Point of (TOP-REAL b1)
for b3 being real number holds Ball b2,b3 = { b4 where B is Point of (TOP-REAL b1) : |.(b4 - b2).| < b3 } ;

:: deftheorem Def2 defines cl_Ball TOPREAL9:def 2 :
for b1 being Nat
for b2 being Point of (TOP-REAL b1)
for b3 being real number holds cl_Ball b2,b3 = { b4 where B is Point of (TOP-REAL b1) : |.(b4 - b2).| <= b3 } ;

:: deftheorem Def3 defines Sphere TOPREAL9:def 3 :
for b1 being Nat
for b2 being Point of (TOP-REAL b1)
for b3 being real number holds Sphere b2,b3 = { b4 where B is Point of (TOP-REAL b1) : |.(b4 - b2).| = b3 } ;

theorem Th7: :: TOPREAL9:7
for b1 being Nat
for b2 being real number
for b3, b4 being Point of (TOP-REAL b1) holds
( b3 in Ball b4,b2 iff |.(b3 - b4).| < b2 )
proof end;

theorem Th8: :: TOPREAL9:8
for b1 being Nat
for b2 being real number
for b3, b4 being Point of (TOP-REAL b1) holds
( b3 in cl_Ball b4,b2 iff |.(b3 - b4).| <= b2 )
proof end;

theorem Th9: :: TOPREAL9:9
for b1 being Nat
for b2 being real number
for b3, b4 being Point of (TOP-REAL b1) holds
( b3 in Sphere b4,b2 iff |.(b3 - b4).| = b2 )
proof end;

theorem Th10: :: TOPREAL9:10
for b1 being Nat
for b2 being real number
for b3 being Point of (TOP-REAL b1) st b3 in Ball (0.REAL b1),b2 holds
|.b3.| < b2
proof end;

theorem Th11: :: TOPREAL9:11
for b1 being Nat
for b2 being real number
for b3 being Point of (TOP-REAL b1) st b3 in cl_Ball (0.REAL b1),b2 holds
|.b3.| <= b2
proof end;

theorem Th12: :: TOPREAL9:12
for b1 being Nat
for b2 being real number
for b3 being Point of (TOP-REAL b1) st b3 in Sphere (0.REAL b1),b2 holds
|.b3.| = b2
proof end;

theorem Th13: :: TOPREAL9:13
for b1 being Nat
for b2 being real number
for b3 being Point of (TOP-REAL b1)
for b4 being Point of (Euclid b1) st b3 = b4 holds
Ball b4,b2 = Ball b3,b2
proof end;

theorem Th14: :: TOPREAL9:14
for b1 being Nat
for b2 being real number
for b3 being Point of (TOP-REAL b1)
for b4 being Point of (Euclid b1) st b3 = b4 holds
cl_Ball b4,b2 = cl_Ball b3,b2
proof end;

theorem Th15: :: TOPREAL9:15
for b1 being Nat
for b2 being real number
for b3 being Point of (TOP-REAL b1)
for b4 being Point of (Euclid b1) st b3 = b4 holds
Sphere b4,b2 = Sphere b3,b2
proof end;

theorem Th16: :: TOPREAL9:16
for b1 being Nat
for b2 being real number
for b3 being Point of (TOP-REAL b1) holds Ball b3,b2 c= cl_Ball b3,b2
proof end;

theorem Th17: :: TOPREAL9:17
for b1 being Nat
for b2 being real number
for b3 being Point of (TOP-REAL b1) holds Sphere b3,b2 c= cl_Ball b3,b2
proof end;

theorem Th18: :: TOPREAL9:18
for b1 being Nat
for b2 being real number
for b3 being Point of (TOP-REAL b1) holds (Ball b3,b2) \/ (Sphere b3,b2) = cl_Ball b3,b2
proof end;

theorem Th19: :: TOPREAL9:19
for b1 being Nat
for b2 being real number
for b3 being Point of (TOP-REAL b1) holds Ball b3,b2 misses Sphere b3,b2
proof end;

registration
let c1 be Nat;
let c2 be Point of (TOP-REAL c1);
let c3 be real non positive number ;
cluster Ball a2,a3 -> empty ;
coherence
Ball c2,c3 is empty
proof end;
end;

registration
let c1 be Nat;
let c2 be Point of (TOP-REAL c1);
let c3 be real positive number ;
cluster Ball a2,a3 -> non empty ;
coherence
not Ball c2,c3 is empty
proof end;
end;

theorem Th20: :: TOPREAL9:20
for b1 being Nat
for b2 being real number
for b3 being Point of (TOP-REAL b1) st not Ball b3,b2 is empty holds
b2 > 0
proof end;

theorem Th21: :: TOPREAL9:21
for b1 being Nat
for b2 being real number
for b3 being Point of (TOP-REAL b1) st Ball b3,b2 is empty holds
b2 <= 0
proof end;

registration
let c1 be Nat;
let c2 be Point of (TOP-REAL c1);
let c3 be real negative number ;
cluster cl_Ball a2,a3 -> empty ;
coherence
cl_Ball c2,c3 is empty
proof end;
end;

registration
let c1 be Nat;
let c2 be Point of (TOP-REAL c1);
let c3 be real non negative number ;
cluster cl_Ball a2,a3 -> non empty ;
coherence
not cl_Ball c2,c3 is empty
proof end;
end;

theorem Th22: :: TOPREAL9:22
for b1 being Nat
for b2 being real number
for b3 being Point of (TOP-REAL b1) st not cl_Ball b3,b2 is empty holds
b2 >= 0
proof end;

theorem Th23: :: TOPREAL9:23
for b1 being Nat
for b2 being real number
for b3 being Point of (TOP-REAL b1) st cl_Ball b3,b2 is empty holds
b2 < 0
proof end;

theorem Th24: :: TOPREAL9:24
for b1 being Nat
for b2, b3, b4 being real number
for b5, b6, b7 being Point of (TOP-REAL b1) st b2 + b3 = 1 & (abs b2) + (abs b3) = 1 & b3 <> 0 & b5 in cl_Ball b6,b4 & b7 in Ball b6,b4 holds
(b2 * b5) + (b3 * b7) in Ball b6,b4
proof end;

registration
let c1 be Nat;
let c2 be Point of (TOP-REAL c1);
let c3 be real number ;
cluster Ball a2,a3 -> open Bounded ;
coherence
( Ball c2,c3 is open & Ball c2,c3 is Bounded )
proof end;
cluster cl_Ball a2,a3 -> closed Bounded ;
coherence
( cl_Ball c2,c3 is closed & cl_Ball c2,c3 is Bounded )
proof end;
cluster Sphere a2,a3 -> closed Bounded ;
coherence
( Sphere c2,c3 is closed & Sphere c2,c3 is Bounded )
proof end;
end;

Lemma18: for b1 being Nat
for b2 being real number
for b3 being Subset of (TOP-REAL b1)
for b4 being Point of (TOP-REAL b1) st b3 = { b5 where B is Point of (TOP-REAL b1) : |.(b5 - b4).| <= b2 } holds
b3 is convex
proof end;

Lemma19: for b1 being Nat
for b2 being real number
for b3 being Subset of (TOP-REAL b1)
for b4 being Point of (TOP-REAL b1) st b3 = { b5 where B is Point of (TOP-REAL b1) : |.(b5 - b4).| < b2 } holds
b3 is convex
proof end;

registration
let c1 be Nat;
let c2 be Point of (TOP-REAL c1);
let c3 be real number ;
cluster Ball a2,a3 -> open Bounded convex ;
coherence
Ball c2,c3 is convex
by Lemma19;
cluster cl_Ball a2,a3 -> closed Bounded convex ;
coherence
cl_Ball c2,c3 is convex
by Lemma18;
end;

definition
let c1 be Nat;
let c2 be Function of (TOP-REAL c1),(TOP-REAL c1);
attr a2 is homogeneous means :Def4: :: TOPREAL9:def 4
for b1 being real number
for b2 being Point of (TOP-REAL a1) holds a2 . (b1 * b2) = b1 * (a2 . b2);
attr a2 is additive means :Def5: :: TOPREAL9:def 5
for b1, b2 being Point of (TOP-REAL a1) holds a2 . (b1 + b2) = (a2 . b1) + (a2 . b2);
end;

:: deftheorem Def4 defines homogeneous TOPREAL9:def 4 :
for b1 being Nat
for b2 being Function of (TOP-REAL b1),(TOP-REAL b1) holds
( b2 is homogeneous iff for b3 being real number
for b4 being Point of (TOP-REAL b1) holds b2 . (b3 * b4) = b3 * (b2 . b4) );

:: deftheorem Def5 defines additive TOPREAL9:def 5 :
for b1 being Nat
for b2 being Function of (TOP-REAL b1),(TOP-REAL b1) holds
( b2 is additive iff for b3, b4 being Point of (TOP-REAL b1) holds b2 . (b3 + b4) = (b2 . b3) + (b2 . b4) );

registration
let c1 be Nat;
cluster (TOP-REAL a1) --> (0.REAL a1) -> homogeneous additive ;
coherence
( (TOP-REAL c1) --> (0.REAL c1) is homogeneous & (TOP-REAL c1) --> (0.REAL c1) is additive )
proof end;
end;

registration
let c1 be Nat;
cluster continuous homogeneous additive M5(the carrier of (TOP-REAL a1),the carrier of (TOP-REAL a1));
existence
ex b1 being Function of (TOP-REAL c1),(TOP-REAL c1) st
( b1 is homogeneous & b1 is additive & b1 is continuous )
proof end;
end;

registration
let c1, c2 be real number ;
cluster AffineMap a1,0,a2,0 -> homogeneous additive ;
coherence
( AffineMap c1,0,c2,0 is homogeneous & AffineMap c1,0,c2,0 is additive )
proof end;
end;

theorem Th25: :: TOPREAL9:25
for b1 being Nat
for b2 being homogeneous additive Function of (TOP-REAL b1),(TOP-REAL b1)
for b3 being convex Subset of (TOP-REAL b1) holds b2 .: b3 is convex
proof end;

definition
let c1 be Nat;
let c2, c3 be Point of (TOP-REAL c1);
func halfline c2,c3 -> Subset of (TOP-REAL a1) equals :: TOPREAL9:def 6
{ (((1 - b1) * a2) + (b1 * a3)) where B is Real : 0 <= b1 } ;
coherence
{ (((1 - b1) * c2) + (b1 * c3)) where B is Real : 0 <= b1 } is Subset of (TOP-REAL c1)
proof end;
end;

:: deftheorem Def6 defines halfline TOPREAL9:def 6 :
for b1 being Nat
for b2, b3 being Point of (TOP-REAL b1) holds halfline b2,b3 = { (((1 - b4) * b2) + (b4 * b3)) where B is Real : 0 <= b4 } ;

theorem Th26: :: TOPREAL9:26
for b1 being Nat
for b2, b3 being Point of (TOP-REAL b1)
for b4 being set holds
( b4 in halfline b2,b3 iff ex b5 being real number st
( b4 = ((1 - b5) * b2) + (b5 * b3) & 0 <= b5 ) )
proof end;

registration
let c1 be Nat;
let c2, c3 be Point of (TOP-REAL c1);
cluster halfline a2,a3 -> non empty ;
coherence
not halfline c2,c3 is empty
proof end;
end;

theorem Th27: :: TOPREAL9:27
for b1 being Nat
for b2, b3 being Point of (TOP-REAL b1) holds b2 in halfline b2,b3
proof end;

theorem Th28: :: TOPREAL9:28
for b1 being Nat
for b2, b3 being Point of (TOP-REAL b1) holds b2 in halfline b3,b2
proof end;

theorem Th29: :: TOPREAL9:29
for b1 being Nat
for b2 being Point of (TOP-REAL b1) holds halfline b2,b2 = {b2}
proof end;

theorem Th30: :: TOPREAL9:30
for b1 being Nat
for b2, b3, b4 being Point of (TOP-REAL b1) st b2 in halfline b3,b4 holds
halfline b3,b2 c= halfline b3,b4
proof end;

theorem Th31: :: TOPREAL9:31
for b1 being Nat
for b2, b3, b4 being Point of (TOP-REAL b1) st b2 in halfline b3,b4 & b2 <> b3 holds
halfline b3,b4 = halfline b3,b2
proof end;

theorem Th32: :: TOPREAL9:32
for b1 being Nat
for b2, b3 being Point of (TOP-REAL b1) holds LSeg b2,b3 c= halfline b2,b3
proof end;

registration
let c1 be Nat;
let c2, c3 be Point of (TOP-REAL c1);
cluster halfline a2,a3 -> non empty convex ;
coherence
halfline c2,c3 is convex
proof end;
end;

theorem Th33: :: TOPREAL9:33
for b1 being Nat
for b2 being real number
for b3, b4, b5 being Point of (TOP-REAL b1) st b3 in Sphere b4,b2 & b5 in Ball b4,b2 holds
(LSeg b3,b5) /\ (Sphere b4,b2) = {b3}
proof end;

theorem Th34: :: TOPREAL9:34
for b1 being Nat
for b2 being real number
for b3, b4, b5 being Point of (TOP-REAL b1) st b3 in Sphere b4,b2 & b5 in Sphere b4,b2 holds
(LSeg b3,b5) \ {b3,b5} c= Ball b4,b2
proof end;

theorem Th35: :: TOPREAL9:35
for b1 being Nat
for b2 being real number
for b3, b4, b5 being Point of (TOP-REAL b1) st b3 in Sphere b4,b2 & b5 in Sphere b4,b2 holds
(LSeg b3,b5) /\ (Sphere b4,b2) = {b3,b5}
proof end;

theorem Th36: :: TOPREAL9:36
for b1 being Nat
for b2 being real number
for b3, b4, b5 being Point of (TOP-REAL b1) st b3 in Sphere b4,b2 & b5 in Sphere b4,b2 holds
(halfline b3,b5) /\ (Sphere b4,b2) = {b3,b5}
proof end;

theorem Th37: :: TOPREAL9:37
for b1 being Nat
for b2, b3 being real number
for b4, b5, b6 being Point of (TOP-REAL b1)
for b7, b8, b9 being Element of REAL b1 st b7 = b4 & b8 = b5 & b9 = b6 & b4 <> b5 & b4 in Ball b6,b2 & b3 = ((- (2 * |((b5 - b4),(b4 - b6))|)) + (sqrt (delta (Sum (sqr (b8 - b7))),(2 * |((b5 - b4),(b4 - b6))|),((Sum (sqr (b7 - b9))) - (b2 ^2 ))))) / (2 * (Sum (sqr (b8 - b7)))) holds
ex b10 being Point of (TOP-REAL b1) st
( {b10} = (halfline b4,b5) /\ (Sphere b6,b2) & b10 = ((1 - b3) * b4) + (b3 * b5) )
proof end;

theorem Th38: :: TOPREAL9:38
for b1 being Nat
for b2, b3 being real number
for b4, b5, b6 being Point of (TOP-REAL b1)
for b7, b8, b9 being Element of REAL b1 st b7 = ((1 / 2) * b4) + ((1 / 2) * b5) & b8 = b5 & b9 = b6 & b4 <> b5 & b4 in Sphere b6,b2 & b5 in cl_Ball b6,b2 holds
ex b10 being Point of (TOP-REAL b1) st
( b10 <> b4 & {b4,b10} = (halfline b4,b5) /\ (Sphere b6,b2) & ( b5 in Sphere b6,b2 implies b10 = b5 ) & ( not b5 in Sphere b6,b2 & b3 = ((- (2 * |((b5 - (((1 / 2) * b4) + ((1 / 2) * b5))),((((1 / 2) * b4) + ((1 / 2) * b5)) - b6))|)) + (sqrt (delta (Sum (sqr (b8 - b7))),(2 * |((b5 - (((1 / 2) * b4) + ((1 / 2) * b5))),((((1 / 2) * b4) + ((1 / 2) * b5)) - b6))|),((Sum (sqr (b7 - b9))) - (b2 ^2 ))))) / (2 * (Sum (sqr (b8 - b7)))) implies b10 = ((1 - b3) * (((1 / 2) * b4) + ((1 / 2) * b5))) + (b3 * b5) ) )
proof end;

registration
let c1 be Nat;
let c2 be Point of (TOP-REAL c1);
let c3 be real negative number ;
cluster Sphere a2,a3 -> empty closed Bounded ;
coherence
Sphere c2,c3 is empty
proof end;
end;

registration
let c1 be non empty Nat;
let c2 be Point of (TOP-REAL c1);
let c3 be real non negative number ;
cluster Sphere a2,a3 -> non empty closed Bounded ;
coherence
not Sphere c2,c3 is empty
proof end;
end;

theorem Th39: :: TOPREAL9:39
for b1 being Nat
for b2 being real number
for b3 being Point of (TOP-REAL b1) st not Sphere b3,b2 is empty holds
b2 >= 0
proof end;

theorem Th40: :: TOPREAL9:40
for b1 being Nat
for b2 being real number
for b3 being Point of (TOP-REAL b1) st not b1 is empty & Sphere b3,b2 is empty holds
b2 < 0
proof end;

theorem Th41: :: TOPREAL9:41
for b1, b2 being real number
for b3, b4 being Point of (TOP-REAL 2) holds ((b1 * b3) + (b2 * b4)) `1 = (b1 * (b3 `1 )) + (b2 * (b4 `1 ))
proof end;

theorem Th42: :: TOPREAL9:42
for b1, b2 being real number
for b3, b4 being Point of (TOP-REAL 2) holds ((b1 * b3) + (b2 * b4)) `2 = (b1 * (b3 `2 )) + (b2 * (b4 `2 ))
proof end;

theorem Th43: :: TOPREAL9:43
for b1, b2, b3 being real number
for b4 being Point of (TOP-REAL 2) holds
( b4 in circle b1,b2,b3 iff |.(b4 - |[b1,b2]|).| = b3 )
proof end;

theorem Th44: :: TOPREAL9:44
for b1, b2, b3 being real number
for b4 being Point of (TOP-REAL 2) holds
( b4 in closed_inside_of_circle b1,b2,b3 iff |.(b4 - |[b1,b2]|).| <= b3 )
proof end;

theorem Th45: :: TOPREAL9:45
for b1, b2, b3 being real number
for b4 being Point of (TOP-REAL 2) holds
( b4 in inside_of_circle b1,b2,b3 iff |.(b4 - |[b1,b2]|).| < b3 )
proof end;

registration
let c1, c2 be real number ;
let c3 be real positive number ;
cluster inside_of_circle a1,a2,a3 -> non empty ;
coherence
not inside_of_circle c1,c2,c3 is empty
proof end;
end;

registration
let c1, c2 be real number ;
let c3 be real non negative number ;
cluster closed_inside_of_circle a1,a2,a3 -> non empty ;
coherence
not closed_inside_of_circle c1,c2,c3 is empty
proof end;
end;

theorem Th46: :: TOPREAL9:46
for b1, b2, b3 being real number holds circle b1,b2,b3 c= closed_inside_of_circle b1,b2,b3
proof end;

theorem Th47: :: TOPREAL9:47
for b1, b2, b3 being real number
for b4 being Point of (Euclid 2) st b4 = |[b1,b2]| holds
cl_Ball b4,b3 = closed_inside_of_circle b1,b2,b3
proof end;

theorem Th48: :: TOPREAL9:48
for b1, b2, b3 being real number
for b4 being Point of (Euclid 2) st b4 = |[b1,b2]| holds
Ball b4,b3 = inside_of_circle b1,b2,b3
proof end;

theorem Th49: :: TOPREAL9:49
for b1, b2, b3 being real number
for b4 being Point of (Euclid 2) st b4 = |[b1,b2]| holds
Sphere b4,b3 = circle b1,b2,b3
proof end;

theorem Th50: :: TOPREAL9:50
for b1, b2, b3 being real number holds Ball |[b1,b2]|,b3 = inside_of_circle b1,b2,b3
proof end;

theorem Th51: :: TOPREAL9:51
for b1, b2, b3 being real number holds cl_Ball |[b1,b2]|,b3 = closed_inside_of_circle b1,b2,b3
proof end;

theorem Th52: :: TOPREAL9:52
for b1, b2, b3 being real number holds Sphere |[b1,b2]|,b3 = circle b1,b2,b3
proof end;

theorem Th53: :: TOPREAL9:53
for b1, b2, b3 being real number holds inside_of_circle b1,b2,b3 c= closed_inside_of_circle b1,b2,b3
proof end;

theorem Th54: :: TOPREAL9:54
for b1, b2, b3 being real number holds inside_of_circle b1,b2,b3 misses circle b1,b2,b3
proof end;

theorem Th55: :: TOPREAL9:55
for b1, b2, b3 being real number holds (inside_of_circle b1,b2,b3) \/ (circle b1,b2,b3) = closed_inside_of_circle b1,b2,b3
proof end;

theorem Th56: :: TOPREAL9:56
for b1 being real number
for b2 being Point of (TOP-REAL 2) st b2 in Sphere (0.REAL 2),b1 holds
((b2 `1 ) ^2 ) + ((b2 `2 ) ^2 ) = b1 ^2
proof end;

theorem Th57: :: TOPREAL9:57
for b1, b2, b3 being real number
for b4, b5 being Point of (TOP-REAL 2) st b4 <> b5 & b4 in closed_inside_of_circle b1,b2,b3 & b5 in closed_inside_of_circle b1,b2,b3 holds
b3 > 0
proof end;

theorem Th58: :: TOPREAL9:58
for b1, b2, b3, b4 being real number
for b5, b6 being Point of (TOP-REAL 2)
for b7, b8, b9 being Element of REAL 2 st b7 = b5 & b8 = b6 & b9 = |[b1,b2]| & b3 = ((- (2 * |((b6 - b5),(b5 - |[b1,b2]|))|)) + (sqrt (delta (Sum (sqr (b8 - b7))),(2 * |((b6 - b5),(b5 - |[b1,b2]|))|),((Sum (sqr (b7 - b9))) - (b4 ^2 ))))) / (2 * (Sum (sqr (b8 - b7)))) & b5 <> b6 & b5 in inside_of_circle b1,b2,b4 holds
ex b10 being Point of (TOP-REAL 2) st
( {b10} = (halfline b5,b6) /\ (circle b1,b2,b4) & b10 = ((1 - b3) * b5) + (b3 * b6) )
proof end;

theorem Th59: :: TOPREAL9:59
for b1, b2, b3 being real number
for b4, b5 being Point of (TOP-REAL 2) st b4 in circle b1,b2,b3 & b5 in inside_of_circle b1,b2,b3 holds
(LSeg b4,b5) /\ (circle b1,b2,b3) = {b4}
proof end;

theorem Th60: :: TOPREAL9:60
for b1, b2, b3 being real number
for b4, b5 being Point of (TOP-REAL 2) st b4 in circle b1,b2,b3 & b5 in circle b1,b2,b3 holds
(LSeg b4,b5) \ {b4,b5} c= inside_of_circle b1,b2,b3
proof end;

theorem Th61: :: TOPREAL9:61
for b1, b2, b3 being real number
for b4, b5 being Point of (TOP-REAL 2) st b4 in circle b1,b2,b3 & b5 in circle b1,b2,b3 holds
(LSeg b4,b5) /\ (circle b1,b2,b3) = {b4,b5}
proof end;

theorem Th62: :: TOPREAL9:62
for b1, b2, b3 being real number
for b4, b5 being Point of (TOP-REAL 2) st b4 in circle b1,b2,b3 & b5 in circle b1,b2,b3 holds
(halfline b4,b5) /\ (circle b1,b2,b3) = {b4,b5}
proof end;

theorem Th63: :: TOPREAL9:63
for b1, b2, b3, b4 being real number
for b5, b6 being Point of (TOP-REAL 2)
for b7, b8, b9 being Element of REAL 2 st b7 = ((1 / 2) * b5) + ((1 / 2) * b6) & b8 = b6 & b9 = |[b1,b2]| & b5 <> b6 & b5 in circle b1,b2,b3 & b6 in closed_inside_of_circle b1,b2,b3 holds
ex b10 being Point of (TOP-REAL 2) st
( b10 <> b5 & {b5,b10} = (halfline b5,b6) /\ (circle b1,b2,b3) & ( b6 in Sphere |[b1,b2]|,b3 implies b10 = b6 ) & ( not b6 in Sphere |[b1,b2]|,b3 & b4 = ((- (2 * |((b6 - (((1 / 2) * b5) + ((1 / 2) * b6))),((((1 / 2) * b5) + ((1 / 2) * b6)) - |[b1,b2]|))|)) + (sqrt (delta (Sum (sqr (b8 - b7))),(2 * |((b6 - (((1 / 2) * b5) + ((1 / 2) * b6))),((((1 / 2) * b5) + ((1 / 2) * b6)) - |[b1,b2]|))|),((Sum (sqr (b7 - b9))) - (b3 ^2 ))))) / (2 * (Sum (sqr (b8 - b7)))) implies b10 = ((1 - b4) * (((1 / 2) * b5) + ((1 / 2) * b6))) + (b4 * b6) ) )
proof end;

registration
let c1, c2, c3 be real number ;
cluster inside_of_circle a1,a2,a3 -> convex ;
coherence
inside_of_circle c1,c2,c3 is convex
proof end;
cluster closed_inside_of_circle a1,a2,a3 -> convex ;
coherence
closed_inside_of_circle c1,c2,c3 is convex
proof end;
end;