localchart / j-bob

The Little Prover

This repository contains "J-Bob", the proof assistant from "The Little Prover" by Daniel P. Friedman and Carl Eastlund, published by MIT Press in 2015. We include the necessary code to run J-Bob in ACL2 and Scheme, as well as a transcript of the proofs in the book. J-Bob is also included in the Dracula package for Racket.

Example of using J-Bob in Scheme, in the scheme/ subdirectory:

;; Load the J-Bob language:
(load "j-bob-lang.scm")
;; Load J-Bob, our little proof assistant:
(load "j-bob.scm")
;; Load the transcript of all proofs in the book:
(load "little-prover.scm")
;; Run every proof in the book, up to and including the proof of align/align:
(dethm.align/align)

Example of using J-Bob in ACL2, in the acl2/ subdirectory:

;; Load the J-Bob language:
(include-book "j-bob-lang")
;; Load J-Bob, our little proof assistant:
(include-book "j-bob")
;; Load the transcript of all proofs in the book:
(include-book "little-prover")
;; Run every proof in the book, up to and including the proof of align/align:
(dethm.align/align)

Example of using J-Bob in Racket, using the Dracula package:

;; Load the J-Bob language:
(include-book "j-bob-lang" :dir :teachpacks)
;; Load J-Bob, our little proof assistant:
(include-book "j-bob" :dir :teachpacks)
;; Load the transcript of all proofs in the book:
(include-book "little-prover" :dir :teachpacks)
;; Run every proof in the book, up to and including the proof of align/align:
(dethm.align/align)

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If you want to load the Scheme version of J-Bob inside DrRacket, you will need to load it in the R5RS language with custom settings:

1. Use the Language menu and the Choose Language ... option.
2. In the dialog box that opens, select Other Languages.
3. Under Legacy Languages choose R5RS.
4. Select Show Details if there is not already a menu on the right of the dialog box.
5. Under Initial Bindings, make sure that Disallow redefinition of initial bindings is unchecked.
6. Then click OK, and J-Bob should work with those settings.