A New Approach to Recursion Removal

Harrison, P.G. and H. Khoshnevisan, A new approach to recursion removal, Theoretical Computer Science 93 (1992) 91-113. Iterative forms are derived for a class of recursive functions, i.e. the recursion is “removed”. The transformation comprises first analysis of the defining equation of a recursive function and then synthesis of an imperative language loop from the primitive subexpressions so obtained. This initially leads to a two-loop program but further transformation provides a single loop version under appropriate conditions. The analysis-synthesis approach contrasts with previous methods using template matching and induces a constructive method which is better suited to mechanisation, although its implementation is not considered here.