Name: Anonymous 2015-01-10 13:17
Originally programs were represented by natural numbers, using
encodings, now called Gödel-numberings, based on the prime factorization theorem. Any standard text on mathematical logic, such as Kleene (1952), contains a thorough account of such representations. The Lisp language (McCarthy, 1965; Allen, 1978) introduced a much more practical and direct representation of syntax as symbolic expressions. These ideas were developed further in the language ML (Gordon et al., 1979), which featured a type system capable of expressing abstract syntax trees.
encodings, now called Gödel-numberings, based on the prime factorization theorem. Any standard text on mathematical logic, such as Kleene (1952), contains a thorough account of such representations. The Lisp language (McCarthy, 1965; Allen, 1978) introduced a much more practical and direct representation of syntax as symbolic expressions. These ideas were developed further in the language ML (Gordon et al., 1979), which featured a type system capable of expressing abstract syntax trees.