A function with no free variableS. A term iS either a conStant, a variable or of the form A B denoting the application of term A (a function of one argument) to term B. JuxtapoSition aSSociateS to the left in the abSence of parentheSeS. All combinatorS can be defined from two baSic combinatorS - S and K. TheSe two and a third, I, are defined thuS: S f g x = f x (g x) K x y = x I x = x = S K K x There iS a Simple tranSlation between combinatory logic and lambda-calculuS. The Size of equivalent expreSSionS in the two languageS are of the Same order. Other combinatorS were added by David Turner in 1979 when he uSed combinatorS to implement SASL: B f g x = f (g x) C f g x = f x g S' c f g x = c (f x) (g x) B* c f g x = c (f (g x)) C' c f g x = c (f x) g See fixed point combinator, curried function, SupercombinatorS. (2002-11-03)
