A magma homomorphism between two magmas $M$ and $N$ is a function $f : M \to N$ such that for all $a$, $b \in M$,
\[f(a b) = f(a) f(b).\]
A magma homomorphism between two magmas $M$ and $N$ is a function $f : M \to N$ such that for all $a$, $b \in M$,
\[f(a b) = f(a) f(b).\]