 of type \(\mathbb{N}^k \rightarrow \mathbb{N}\). As an example, suppose that \(f\) is the multiplication function \(\textit{mult}(x,y)\), \(g_0\) is the constant 3 function (which we may think of as implicitly taking a single argument), and \(g_1(x)\) is the successor function \(s(x)\). Then the composition of \(f\) with \(g_0\) and \(g_1\) is the unary function \(h(x) = f(g_0(x),g_1(x)) = mult(3, s(x))\) which we would conventionally denote by \(3 \times (x+1)\).