Carp is statically-typed with type inference so writing (the Int x) would be enough for the compiler to forbid any usage of x as another type. Writing (Int.+ x

Carp is statically-typed with type inference so writing (the Int x) would be enough for the compiler to forbid any usage of x as another type. Writing (Int.+ x 1) would accomplish the same as Int.+ only accepts Int. You can also annotate function with a type signature. (sig add (Fn [Int Int] Int)) (defn add [x y] (+ x y)) Is the same as: (defn add [x y] (the Int (+ (the Int x) (the Int y))))