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Parametric Types

• Type definitions with similar structure:
  • type BoolPair = Bool x Bool
  • type IntPair = Int x Int
• Use parametric definition:
  • type Pair[T] = T x T
  • type PairOfBool = Pair[Bool]
  • type PairOfInt = Pair[Int]
• Type operators are not types:
  • type A[T] = T -> T
  • type B = forall T. T -> T
  • Different notions!