Strong Call by Value is Reasonable for Time

Abstract

The invariance thesis of Slot and van Emde Boas states that all reasonable models of computation simulate each other with polynomially bounded overhead in time and constant-factor overhead in space. In this paper we show that a family of strong call-by-value strategies in the $\lambda$-calculus are reasonable for time. The proof is based on a construction of an appropriate abstract machine, systematically derived using Danvy et al.'s functional correspondence that connects higher-order interpreters with abstract-machine models by a well-established transformation technique. This is the first machine that implements a strong CbV strategy and simulates $\beta$-reduction with the overhead polynomial in the number of $\beta$-steps and in the size of the initial term. We prove this property using a form of amortized cost analysis à la Okasaki.

31 pages, 7 figures