now let i,
n be
Element of
NAT ;
( i in Seg n implies ( dom (proj i,n) = REAL n & rng (proj i,n) = REAL ) )assume A1:
i in Seg n
;
( dom (proj i,n) = REAL n & rng (proj i,n) = REAL )thus
dom (proj i,n) = REAL n
by FUNCT_2:def 1;
rng (proj i,n) = REAL
proj i,
n is
onto
by A1, Lm2;
hence
rng (proj i,n) = REAL
by FUNCT_2:def 3;
verum end;
hence
( ( for i, n being Element of NAT st i in Seg n holds
( dom (proj i,n) = REAL n & rng (proj i,n) = REAL ) ) & ( for x being Element of REAL holds
( (proj 1,1) . <*x*> = x & ((proj 1,1) " ) . x = <*x*> ) ) )
by Lm1; verum