let R be domRing; :: thesis: for n being non empty Ordinal
for m being non zero Nat
for P being Subset of (singletons (Funcs (n,([#] R)))) st card P = m holds
union P is Algebraic_Set of n,R

let n be non empty Ordinal; :: thesis: for m being non zero Nat
for P being Subset of (singletons (Funcs (n,([#] R)))) st card P = m holds
union P is Algebraic_Set of n,R

let m be non zero Nat; :: thesis: for P being Subset of (singletons (Funcs (n,([#] R)))) st card P = m holds
union P is Algebraic_Set of n,R

let P be Subset of (singletons (Funcs (n,([#] R)))); :: thesis: ( card P = m implies union P is Algebraic_Set of n,R )
assume A1: card P = m ; :: thesis: union P is Algebraic_Set of n,R
A2: singletons (Funcs (n,([#] R))) c= Alg_Sets (n,R)
proof
for o being object st o in singletons (Funcs (n,([#] R))) holds
o in Alg_Sets (n,R)
proof
let o be object ; :: thesis: ( o in singletons (Funcs (n,([#] R))) implies o in Alg_Sets (n,R) )
assume o in singletons (Funcs (n,([#] R))) ; :: thesis: o in Alg_Sets (n,R)
then o in { S where S is Subset of (Funcs (n,([#] R))) : S is 1 -element } by BSPACE:def 8;
then consider S being Subset of (Funcs (n,([#] R))) such that
A4: ( o = S & S is 1 -element ) ;
consider p being Element of Funcs (n,([#] R)) such that
A5: S = {p} by A4, CARD_1:65;
S is Algebraic_Set of n,R by A5, Th26;
hence o in Alg_Sets (n,R) by A4; :: thesis: verum
end;
hence singletons (Funcs (n,([#] R))) c= Alg_Sets (n,R) ; :: thesis: verum
end;
P c= Alg_Sets (n,R) by A2;
hence union P is Algebraic_Set of n,R by A1, Th24; :: thesis: verum