set TR = TOP-REAL n;
set cTR = the carrier of (TOP-REAL n);
let f be Function of (TOP-REAL n),(TOP-REAL n); ( f is homogeneous & f is additive & f is rotation implies f is being_homeomorphism )
assume A1:
( f is homogeneous & f is additive & f is rotation )
; f is being_homeomorphism
then reconsider F = f as additive homogeneous Function of (TOP-REAL n),(TOP-REAL n) ;
set M = AutMt F;
per cases
( Det (AutMt F) = 1. F_Real or ( Det (AutMt F) = - (1. F_Real) & not f is base_rotation ) )
by A1, Th37, Th38;
suppose A2:
(
Det (AutMt F) = - (1. F_Real) & not
f is
base_rotation )
;
f is being_homeomorphism
n <> 0
then A5:
n in Seg n
by FINSEQ_1:3;
A6:
dom f = the
carrier of
(TOP-REAL n)
by FUNCT_2:52;
set A =
AxialSymmetry (
n,
n);
set MA =
Mx2Tran (AxialSymmetry (n,n));
A7:
(Mx2Tran (AxialSymmetry (n,n))) " is
being_homeomorphism
by TOPS_2:56;
A8:
(
Mx2Tran (AxialSymmetry (n,n)) is
one-to-one &
rng (Mx2Tran (AxialSymmetry (n,n))) = [#] (TOP-REAL n) )
by TOPS_2:def 5;
AutMt (Mx2Tran (AxialSymmetry (n,n))) = AxialSymmetry (
n,
n)
by Def6;
then A9:
f * (Mx2Tran (AxialSymmetry (n,n))) is
base_rotation
by A1, A2, A5, Th39;
(f * (Mx2Tran (AxialSymmetry (n,n)))) * ((Mx2Tran (AxialSymmetry (n,n))) ") =
f * ((Mx2Tran (AxialSymmetry (n,n))) * ((Mx2Tran (AxialSymmetry (n,n))) "))
by RELAT_1:36
.=
f * (id the carrier of (TOP-REAL n))
by A8, TOPS_2:52
.=
f
by A6, RELAT_1:51
;
hence
f is
being_homeomorphism
by A9, A7, TOPS_2:57;
verum end; end;