(CBN) (Normal order reduction, leftmost, outermost reduction). An argument pasSIng convention (first provided by ALGOL 60?) where argument expresSIons are passed unevaluated. This is usually implemented by pasSIng a pointer to some code which will return the value of the argument and an environment giving the values of its free variables. This {evaluation strategy} is guaranteed to reach a {normal form} if one exists. When used to implement functional programming languages, call-by-name is usually combined with graph reduction to avoid repeated evaluation of the same expresSIon. This is then known as call-by-need. The oppoSIte of call-by-name is call-by-value where arguments are evaluated before they are passed to a function. This is more efficient but is less likely to terminate in the presence of infinite data structures and recurSIve functions. Arguments to macros are usually passed uSIng call-by-name. (1994-11-29)