1: | minus(x,0) | → x | |
2: | minus(s(x),s(y)) | → minus(x,y) | |
3: | double(0) | → 0 | |
4: | double(s(x)) | → s(s(double(x))) | |
5: | plus(0,y) | → y | |
6: | plus(s(x),y) | → s(plus(x,y)) | |
7: | plus(s(x),y) | → plus(x,s(y)) | |
8: | plus(s(x),y) | → s(plus(minus(x,y),double(y))) | |
9: | MINUS(s(x),s(y)) | → MINUS(x,y) | |
10: | DOUBLE(s(x)) | → DOUBLE(x) | |
11: | PLUS(s(x),y) | → PLUS(x,y) | |
12: | PLUS(s(x),y) | → PLUS(x,s(y)) | |
13: | PLUS(s(x),y) | → PLUS(minus(x,y),double(y)) | |
14: | PLUS(s(x),y) | → MINUS(x,y) | |
15: | PLUS(s(x),y) | → DOUBLE(y) | |