NO
Input TRS:
      1: and(true()) -> X
      2: if(true()) -> X
      3: if(false()) -> Y
      4: add(0()) -> X
      5: and(false()) -> false()
      6: add(s()) -> s()
      7: first(0(),X) -> nil()
      8: first(s(),cons()) -> cons()
      9: from() -> cons()
Extra variable in rule 2.