 In practice, the programming technique of closures can be used to perform partial application and a kind of currying, by hiding arguments in an environment that travels with the curried function.Suppose we have a function formula_16 which takes two real arguments and outputs real numbers, and it is defined by formula_17.Currying translates this into a function formula_18 which takes a single real argument and outputs functions from formula_19 to formula_19.