let r be Real; :: thesis: for A being symmetrical Subset of COMPLEX
for F being PartFunc of REAL ,REAL st F is_odd_on A holds
r (#) F is_odd_on A
let A be symmetrical Subset of COMPLEX ; :: thesis: for F being PartFunc of REAL ,REAL st F is_odd_on A holds
r (#) F is_odd_on A
let F be PartFunc of REAL ,REAL ; :: thesis: ( F is_odd_on A implies r (#) F is_odd_on A )
assume
F is_odd_on A
; :: thesis: r (#) F is_odd_on A
then A1:
( A c= dom F & F | A is odd )
by Def8;
A2:
A c= dom (r (#) F)
by A1, VALUED_1:def 5;
A3:
dom ((r (#) F) | A) = A
by RELAT_1:91, A2;
for x being Real st x in dom ((r (#) F) | A) & - x in dom ((r (#) F) | A) holds
((r (#) F) | A) . (- x) = - (((r (#) F) | A) . x)
proof
let x be
Real;
:: thesis: ( x in dom ((r (#) F) | A) & - x in dom ((r (#) F) | A) implies ((r (#) F) | A) . (- x) = - (((r (#) F) | A) . x) )
assume A5:
(
x in dom ((r (#) F) | A) &
- x in dom ((r (#) F) | A) )
;
:: thesis: ((r (#) F) | A) . (- x) = - (((r (#) F) | A) . x)
then A6:
(
x in dom (F | A) &
- x in dom (F | A) )
by RELAT_1:91, A1, A3;
((r (#) F) | A) . (- x) =
((r (#) F) | A) /. (- x)
by PARTFUN1:def 8, A5
.=
(r (#) F) /. (- x)
by PARTFUN2:35, A2, A3, A5
.=
(r (#) F) . (- x)
by PARTFUN1:def 8, A2, A3, A5
.=
r * (F . (- x))
by VALUED_1:def 5, A2, A3, A5
.=
r * (F /. (- x))
by PARTFUN1:def 8, A3, A1, A5
.=
r * ((F | A) /. (- x))
by PARTFUN2:35, A1, A3, A5
.=
r * ((F | A) . (- x))
by PARTFUN1:def 8, A6
.=
r * (- ((F | A) . x))
by A1, Def6, A6
.=
- (r * ((F | A) . x))
.=
- (r * ((F | A) /. x))
by PARTFUN1:def 8, A6
.=
- (r * (F /. x))
by PARTFUN2:35, A1, A3, A5
.=
- (r * (F . x))
by PARTFUN1:def 8, A1, A3, A5
.=
- ((r (#) F) . x)
by VALUED_1:def 5, A2, A3, A5
.=
- ((r (#) F) /. x)
by PARTFUN1:def 8, A2, A3, A5
.=
- (((r (#) F) | A) /. x)
by PARTFUN2:35, A2, A3, A5
.=
- (((r (#) F) | A) . x)
by PARTFUN1:def 8, A5
;
hence
((r (#) F) | A) . (- x) = - (((r (#) F) | A) . x)
;
:: thesis: verum
end;
then
( (r (#) F) | A is with_symmetrical_domain & (r (#) F) | A is quasi_odd )
by Def6, A3, Def2;
hence
r (#) F is_odd_on A
by A2, Def8; :: thesis: verum