| 1: | fib(N) | → sel(N,fib1(s(0),s(0))) | |
| 2: | fib1(X,Y) | → cons(X,fib1(Y,add(X,Y))) | |
| 3: | add(0,X) | → X | |
| 4: | add(s(X),Y) | → s(add(X,Y)) | |
| 5: | sel(0,cons(X,XS)) | → X | |
| 6: | sel(s(N),cons(X,XS)) | → sel(N,XS) | |
| 7: | FIB(N) | → SEL(N,fib1(s(0),s(0))) | |
| 8: | FIB(N) | → FIB1(s(0),s(0)) | |
| 9: | FIB1(X,Y) | → FIB1(Y,add(X,Y)) | |
| 10: | FIB1(X,Y) | → ADD(X,Y) | |
| 11: | ADD(s(X),Y) | → ADD(X,Y) | |
| 12: | SEL(s(N),cons(X,XS)) | → SEL(N,XS) | |