 These examples illustrate that the simpler recursion schemes which are employed in many informal recursive definitions may be assimilated to  Definition 2.3—e.g.,  the function \(h(x,y)\) defined in (\ref{prex3}) maybe obtained as \(\mathcal{PrimRec}_1[f,\mathcal{Comp}^2_3[g,\pi^3_1,\pi^3_2]]\). Repeated use of this and similar observations will be made (generally without comment) in the examples provided in  Section 2.1.2.