set Z = { x where x is Function of n,R : for p being Polynomial of n,R st p in S holds
eval (p,x) = 0. R } ;
{ x where x is Function of n,R : for p being Polynomial of n,R st p in S holds
eval (p,x) = 0. R } c= Funcs (n,([#] R))
proof
let z be
object ;
TARSKI:def 3 ( not z in { x where x is Function of n,R : for p being Polynomial of n,R st p in S holds
eval (p,x) = 0. R } or z in Funcs (n,([#] R)) )
assume
z in { x where x is Function of n,R : for p being Polynomial of n,R st p in S holds
eval (p,x) = 0. R }
;
z in Funcs (n,([#] R))
then consider x being
Function of
n,
R such that A2:
(
z = x & ( for
p being
Polynomial of
n,
R st
p in S holds
eval (
p,
x)
= 0. R ) )
;
thus
z in Funcs (
n,
([#] R))
by A2, FUNCT_2:8;
verum
end;
hence
( ( S <> {} implies { x where x is Function of n,R : for p being Polynomial of n,R st p in S holds
eval (p,x) = 0. R } is Subset of (Funcs (n,([#] R))) ) & ( not S <> {} implies {} is Subset of (Funcs (n,([#] R))) ) )
by XBOOLE_1:2; verum