| 1: | x - 0 | → x | |
| 2: | 0 - s(y) | → 0 | |
| 3: | s(x) - s(y) | → x - y | |
| 4: | lt(x,0) | → false | |
| 5: | lt(0,s(y)) | → true | |
| 6: | lt(s(x),s(y)) | → lt(x,y) | |
| 7: | if(true,x,y) | → x | |
| 8: | if(false,x,y) | → y | |
| 9: | div(x,0) | → 0 | |
| 10: | div(0,y) | → 0 | |
| 11: | div(s(x),s(y)) | → if(lt(x,y),0,s(div(x - y,s(y)))) | |
| 12: | s(x) -# s(y) | → x -# y | |
| 13: | LT(s(x),s(y)) | → LT(x,y) | |
| 14: | DIV(s(x),s(y)) | → IF(lt(x,y),0,s(div(x - y,s(y)))) | |
| 15: | DIV(s(x),s(y)) | → LT(x,y) | |
| 16: | DIV(s(x),s(y)) | → DIV(x - y,s(y)) | |
| 17: | DIV(s(x),s(y)) | → x -# y | |