Least fixed points revisited

Parameter mechanisms for recursive procedures are investigated. Contrary to the view of Manna et al., it is argued that both call-by-value and call-by-name mechanisms yield the least fixed points of the functionals determined by the bodies of the procedures concerned. These functionals differ, however, according to the mechanism chosen. A careful and detailed presentation of this result is given, along the lines of a simple typed lambda calculus, with interpretation rules modelling program execution in such a way that call-by-value determines a change in the environment and call-by-name a textual substitution in the procedure body