| 1: | plus(x,0) | → x | |
| 2: | plus(x,s(y)) | → s(plus(x,y)) | |
| 3: | times(0,y) | → 0 | |
| 4: | times(x,0) | → 0 | |
| 5: | times(s(x),y) | → plus(times(x,y),y) | |
| 6: | p(s(s(x))) | → s(p(s(x))) | |
| 7: | p(s(0)) | → 0 | |
| 8: | fac(s(x)) | → times(fac(p(s(x))),s(x)) | |
| 9: | PLUS(x,s(y)) | → PLUS(x,y) | |
| 10: | TIMES(s(x),y) | → PLUS(times(x,y),y) | |
| 11: | TIMES(s(x),y) | → TIMES(x,y) | |
| 12: | P(s(s(x))) | → P(s(x)) | |
| 13: | FAC(s(x)) | → TIMES(fac(p(s(x))),s(x)) | |
| 14: | FAC(s(x)) | → FAC(p(s(x))) | |
| 15: | FAC(s(x)) | → P(s(x)) | |