Lean vs SPIN

Lean is an open-source programming language and proof assistant for formalizing mathematics, verifying software, and writing general code. Its minimal trusted kernel checks proofs, and the project describes it as supporting correctness in mathematical, software, and hardware verification. Lean includes the Grind tool for automating some pattern matching, case analysis, and systems of linear inequalities; metaprogramming lets users add notation and proof automation. Projects are managed with Lake, the package manager bundled with Lean. Mathlib is a community-driven library with over a million lines spanning areas including algebra, analysis, topology, probability, and computer science. The recommended setup uses VS Code with the Lean 4 extension for syntax highlighting and code completion, while Neovim with lean.nvim is also well-supported. Lean runs on Linux, macOS, and Windows, and Lean4Web lets users run code in a browser. The software is free under the Apache 2.0 license. Learning resources include textbooks, tutorials, interactive games, documentation, and an API reference.

SPIN is a free, self-hosted model-checking tool for analyzing the logical consistency of asynchronous systems, including distributed software and communication protocols. Systems are specified in Promela, which represents asynchronous processes, nondeterministic choices, loops, and local or global variables. Models can state correctness requirements, including linear temporal logic. SPIN supports interactive, guided, and random simulations of execution. For verification, it generates a C program for exhaustive or approximate checking of those requirements. Its product description lists detection of deadlocks, race conditions, incomplete specifications, and unjustified assumptions about process speeds. Partial order reduction optimizes verification runs, while the site provides guidance for multicore depth-first and breadth-first algorithms and swarm methods for large state spaces. SPIN runs on Linux, macOS, and Windows, as well as other listed systems. From version 6.4.5, its code, sources, and executables use the BSD 3-Clause license. Verification requires a working C compiler and preprocessor. The optional iSpin graphical interface is written in Tcl/Tk and requires Tcl/Tk.