Why are λ-calculus optimal evaluators able to compute big modular exponentiations without formulas?
The phenomenon comes from the amount of shared beta-reduction steps, which can be dramatically different in Haskell-style lazy evaluation (or usual call-by-value, which is not that far in this respect) and in Vuillemin-Lévy-Lamping-Kathail-Asperti-Guerrini-(et al…) “optimal” evaluation. This is a general feature, that is completely independent from the arithmetic formulas you could use in this particular … Read more