An implementation of the Strong Exponential Substitution Abstract Machine without Erasure (SESAME) described in the paper.
"IMELL Cut Elimination with Linear Overhead" by B. Accattoli and C. Sacerdoti Coen, submitted at FSCD 2024.
The sesame executable implements a REPL (Read Eval Print Loop) to evaluate Intuitionistic Multiplicative Exponential Linear Logic (IMELL) terms. The loop asks the user to enter a term, checks the term for properness and then evaluates it, showing all reduction steps.
The terms are encoded in the Exponential Substitution Calculus (ESC) syntax. The implementation is based on term graphs. Reduction takes time which is bi-linear in the size of the initial term and the number of exponential/multiplicative steps of IMELL.
Before starting the REPL loop, some example terms are evaluated. Among them there are examples from a family of terms that perform a number of exponential steps without even a single multiplicative steps. They show that, contrarily to what happens for lambda-calculi, the number of beta-steps alone is not a cost model.
Searchable documentation for every datatype and function can be found at https://sacerdot.github.io/sesame.
To compile sesame, one needs a working installation of OCaml and Dune. The simplest way is to use the OPAM package manager for OCaml:
- Install OPAM https://opam.ocaml.org/doc/Install.html
- Install dune, odoc and sherlodoc via opam:
opam update && opam install dune odoc sherlodoc
- [optional] Compile sesame's documentation via dune and open it in a browser:
opam build @doc && open _build/default/_doc/_html/sesame/index.html
The same documentation can be found at https://sacerdot.github.io/sesame - Run sesame's REPL:
opam exec sesame
The input grammar is printed by the REPL itself.