let n be non empty Nat; RealFuncExtMult (Seg n) = n -Mult_over F_Real
set OP1 = RealFuncExtMult (Seg n);
set OP2 = n -Mult_over F_Real;
A1:
Funcs ((Seg n),REAL) = REAL n
by FINSEQ_2:93;
for x being Element of REAL
for y being Element of REAL n holds (RealFuncExtMult (Seg n)) . (x,y) = (n -Mult_over F_Real) . (x,y)
proof
let x be
Element of
REAL ;
for y being Element of REAL n holds (RealFuncExtMult (Seg n)) . (x,y) = (n -Mult_over F_Real) . (x,y)let y be
Element of
REAL n;
(RealFuncExtMult (Seg n)) . (x,y) = (n -Mult_over F_Real) . (x,y)
reconsider y0 =
y as
Element of
Funcs (
(Seg n),
REAL)
by FINSEQ_2:93;
[x,y] in [:REAL,(REAL n):]
by ZFMISC_1:87;
then
(n -Mult_over F_Real) . (
x,
y)
in REAL n
by FUNCT_2:5;
then reconsider h =
(n -Mult_over F_Real) . (
x,
y0) as
Element of
Funcs (
(Seg n),
REAL)
by FINSEQ_2:93;
for
i being
Element of
Seg n holds
h . i = x * (y0 . i)
hence
(RealFuncExtMult (Seg n)) . (
x,
y)
= (n -Mult_over F_Real) . (
x,
y)
by FUNCSDOM:4;
verum
end;
hence
RealFuncExtMult (Seg n) = n -Mult_over F_Real
by BINOP_1:2, A1; verum