Solution
= Solution
Define $A(0,m)=m$ and $A(n+1,m)=S(A(n,m))$. This is primitive recursion from a projection and successor, so $A(n,m)=n+m$ is <primitive recursive function>.
= Solution
Define $A(0,m)=m$ and $A(n+1,m)=S(A(n,m))$. This is primitive recursion from a projection and successor, so $A(n,m)=n+m$ is <primitive recursive function>.