A(dministrative?)-Normal Form

In Lecture 4, Ben Lerner defined ANF and gave examples of converting expressions into ANF.

Let's practice checking and converting expressions into A-Normal Form (ANF). I have several example expr below. For each expression, indicate if it is in ANF or not. If it isn't in ANF, indicate why, and then convert it to ANF.

Num 42L
Add1 (Num 3L))
Prim2 (Plus, Num 1L, Add1 (Num 3L))
Ifnz (Num 1L, Add1 ( Num 2L), Num 4L)
Ifnz (Let ("x", Num 1L, Id "x"), Num 10L, Num 20L))
Let ("x", Num 1L, Add1 (Add1 (Id "x")))
Let ("x", Ifnz (Num 0L, Num 1L, Num 2L), Id "x")
Let ("x", Ifnz (Num 0L, Num 1L, Add1 (Num 2L)), Id "x")
Ifnz (Num 0L, Num 1L, Add1 (Add1 (Num 2L)))
Ifnz (Num 0L, Num 1L, Let ("x", Num 2L, Add1 (Id "x")))