1. A : Type
2. f : A(A + Top)
3. x : A 4. isl(f(x))
5. n :
6. 0 < n 7. (primrec(n - 1;f o p-id() ;i,g. f o g )(x))
7. ~
7. (primrec(n - 1;p-id();i,g. f o g )(outl(f(x))))
(primrec(n;f o p-id() ;i,g. f o g )(x)) ~ (primrec(n;p-id();i,g. f o g )(outl(f(x))))
C1: 8. n = 0
C1: (f o p-id() (x)) ~ (p-id()(outl(f(x))))
C2: .....falsecase..... NILNIL
C2: 8. (n = 0)
C2: ((i,g. f o g )((n - 1),primrec(n - 1;f o p-id() ;i,g. f o g ),x))
C2: ~
C2: ((i,g. f o g )((n - 1),primrec(n - 1;p-id();i,g. f o g ),outl(f(x))))
C.