Exponentiation
Exponentiation is a mathematical operation, written as , involving two numbers, the "base" and the "exponent" . When is a positive integer, exponentiation corresponds to repeated multiplication of the base: that is, is the product of multiplying bases:
Church encoding
The exponentiation function formula_13 is given by the definition of Church numerals; formula_14. In the definition substitute formula_15 to get formula_16 and,
which gives the lambda expression,