Proposition. If
is free in
on
and
is any algebra in
and
, then there is a unique homomorphism
with
for each
. (In other words,
you can aim the generators of
at any elements of any
algebra in
and find a homomorphism that takes the
generators there.)
Corollary 1. Up to isomorphism, there is only one free algebra in
on
generators.
Let us call this algebra
.
Corollary 2. Every
-generated algebra of
is a homomorphic
image of
.
Corollary 3. If
is finite, then it is the largest
-generated algebra in
, and the only one of its size (up to
isomorphism).