let n be Nat; for p being Point of (TOP-REAL n)
for r being Real
for f being additive homogeneous rotation Function of (TOP-REAL n),(TOP-REAL n) st f is onto holds
( f .: (Ball (p,r)) = Ball ((f . p),r) & f .: (cl_Ball (p,r)) = cl_Ball ((f . p),r) & f .: (Sphere (p,r)) = Sphere ((f . p),r) )
let p be Point of (TOP-REAL n); for r being Real
for f being additive homogeneous rotation Function of (TOP-REAL n),(TOP-REAL n) st f is onto holds
( f .: (Ball (p,r)) = Ball ((f . p),r) & f .: (cl_Ball (p,r)) = cl_Ball ((f . p),r) & f .: (Sphere (p,r)) = Sphere ((f . p),r) )
let r be Real; for f being additive homogeneous rotation Function of (TOP-REAL n),(TOP-REAL n) st f is onto holds
( f .: (Ball (p,r)) = Ball ((f . p),r) & f .: (cl_Ball (p,r)) = cl_Ball ((f . p),r) & f .: (Sphere (p,r)) = Sphere ((f . p),r) )
set TR = TOP-REAL n;
let f be additive homogeneous rotation Function of (TOP-REAL n),(TOP-REAL n); ( f is onto implies ( f .: (Ball (p,r)) = Ball ((f . p),r) & f .: (cl_Ball (p,r)) = cl_Ball ((f . p),r) & f .: (Sphere (p,r)) = Sphere ((f . p),r) ) )
assume
f is onto
; ( f .: (Ball (p,r)) = Ball ((f . p),r) & f .: (cl_Ball (p,r)) = cl_Ball ((f . p),r) & f .: (Sphere (p,r)) = Sphere ((f . p),r) )
A2: - (f . p) =
(- 1) * (f . p)
by RLVECT_1:16
.=
f . ((- 1) * p)
by TOPREAL9:def 4
.=
f . (- p)
by RLVECT_1:16
;
A3:
rng f = the carrier of (TOP-REAL n)
by FUNCT_2:def 3;
thus
f .: (Ball (p,r)) = Ball ((f . p),r)
( f .: (cl_Ball (p,r)) = cl_Ball ((f . p),r) & f .: (Sphere (p,r)) = Sphere ((f . p),r) )proof
thus
f .: (Ball (p,r)) c= Ball (
(f . p),
r)
XBOOLE_0:def 10 Ball ((f . p),r) c= f .: (Ball (p,r))
let y be
object ;
TARSKI:def 3 ( not y in Ball ((f . p),r) or y in f .: (Ball (p,r)) )
assume A8:
y in Ball (
(f . p),
r)
;
y in f .: (Ball (p,r))
then consider x being
object such that A9:
x in dom f
and A10:
f . x = y
by A3, FUNCT_1:def 3;
reconsider x =
x as
Point of
(TOP-REAL n) by A9;
(f . x) - (f . p) = f . (x - p)
by A2, VECTSP_1:def 20;
then A11:
|.((f . x) - (f . p)).| = |.(x - p).|
by MATRTOP3:def 4;
|.((f . x) - (f . p)).| < r
by A8, A10, TOPREAL9:7;
then
x in Ball (
p,
r)
by A11;
hence
y in f .: (Ball (p,r))
by A9, A10, FUNCT_1:def 6;
verum
end;
thus
f .: (cl_Ball (p,r)) = cl_Ball ((f . p),r)
f .: (Sphere (p,r)) = Sphere ((f . p),r)proof
thus
f .: (cl_Ball (p,r)) c= cl_Ball (
(f . p),
r)
XBOOLE_0:def 10 cl_Ball ((f . p),r) c= f .: (cl_Ball (p,r))
let y be
object ;
TARSKI:def 3 ( not y in cl_Ball ((f . p),r) or y in f .: (cl_Ball (p,r)) )
assume A16:
y in cl_Ball (
(f . p),
r)
;
y in f .: (cl_Ball (p,r))
then consider x being
object such that A17:
x in dom f
and A18:
f . x = y
by A3, FUNCT_1:def 3;
reconsider x =
x as
Point of
(TOP-REAL n) by A17;
(f . x) - (f . p) = f . (x - p)
by A2, VECTSP_1:def 20;
then A19:
|.((f . x) - (f . p)).| = |.(x - p).|
by MATRTOP3:def 4;
|.((f . x) - (f . p)).| <= r
by A16, A18, TOPREAL9:8;
then
x in cl_Ball (
p,
r)
by A19;
hence
y in f .: (cl_Ball (p,r))
by A17, A18, FUNCT_1:def 6;
verum
end;
thus
f .: (Sphere (p,r)) c= Sphere ((f . p),r)
XBOOLE_0:def 10 Sphere ((f . p),r) c= f .: (Sphere (p,r))
let y be object ; TARSKI:def 3 ( not y in Sphere ((f . p),r) or y in f .: (Sphere (p,r)) )
assume A24:
y in Sphere ((f . p),r)
; y in f .: (Sphere (p,r))
then consider x being object such that
A25:
x in dom f
and
A26:
f . x = y
by A3, FUNCT_1:def 3;
reconsider x = x as Point of (TOP-REAL n) by A25;
(f . x) - (f . p) = f . (x - p)
by A2, VECTSP_1:def 20;
then A27:
|.((f . x) - (f . p)).| = |.(x - p).|
by MATRTOP3:def 4;
|.((f . x) - (f . p)).| = r
by A24, A26, TOPREAL9:9;
then
x in Sphere (p,r)
by A27;
hence
y in f .: (Sphere (p,r))
by A25, A26, FUNCT_1:def 6; verum