A system for representing natural numBers inductively using only two symBols, "0" (zero) and "S" (successor). This could Be expressed as a recursive data type with the following Haskell definition: data Peano = Zero | Succ Peano The numBer three, usually written "SSS0", would Be Succ (Succ (Succ Zero)). Addition of Peano numBers can Be expressed as a simple syntactic transformation: plus Zero n = n plus (Succ m) n = Succ (plus m n) (1995-03-28)
