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164 Stars 37 Forks BSD 3-Clause "New" or "Revised" License 3.8K Commits 202 Opened issues


The symbolic execution engine powering the K Framework

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The Kore Language

Kore is the "core" part of the K framework.

What is Kore all about?

In short, we need a formal semantics of K. In K, users can define formal syntax and semantics of programming languages as K definitions, and automatically obtain parsers, interpreters, compilers, and various verification tools for their languages. Therefore K is a language-independent framework.

Thanks to years of research in matching logic and reachability logic, we know that all K does can be nicely formalized as logic reasoning in matching logic. To give K a formal semantics, we only need to formally specify the underlying matching logic theories with which K does reasoning. In practice, these underlying theories are complex and often infinite, and it is tricky to specify infinite theories without a carefully designed formal specification language. And Kore is such a language.

Structure of this project

The docs directory contains a collection of documents that describe the mathematical foundation of Kore and a BNF grammar that defines the syntax of Kore language. See /docs/ for an overview of the components of Kore.


project is an implementation in Haskell of a Kore parser and symbolic execution engine, for use with the K Framework as a backend.


Besides git, you will need stack or cabal to build

stack build kore
# or
cabal build kore

If using

, version 3.0 or later is recommended.

Using make:

make all # builds all binaries

Apple Silicon

If you are building the project on an Apple Silicon machine, a temporary workaround is necessary to install a new enough version of GHC with support for ARM64 Darwin. To do so, follow the instructions in this comment. The command-line flags for

should then be specified everywhere an execution of
is required. For
invocations in this project, set the environment variable
STACK_BUILD_OPTS=--compiler ghc-8.10.7 --system-ghc


merge their full support for ARM64 Darwin in future releases, it should be possible to remove this workaround.


Developers will require all the dependencies listed above, in addition to the requirements and recommendations below.

Required dependencies

For integration testing, we require:

Instead of installing the frontend, you can use our

to run the integration tests inside a container. Use
to run commands inside the container:
./docker/  # run once when dependencies change
./docker/ make all  # build the backend
./docker/ make test  # run all tests
./docker/ make -C test/imp test  # run all tests in test/imp

Recommended dependencies

For setting up a development environment, we recommend:

  • direnv to make the project's tools available in shells and editors.
  • haskell-language-server, a language server for Haskell that is compatible with most editors. See instructions below to run a language server.
  • hlint for compliance with project guidelines.
  • entr and fd for running
    to keep important files up-to-date.

We recommend to keep

running in the background to keep important files (such as package descriptions) up-to-date, especially if the developer is using Cabal.

Running a language server

To run a language server, developers will need to activate the appropriate

ln -s hie-stack.yaml hie.yaml  # for Stack
# or
ln -s hie-cabal.yaml hie.yaml  # for Cabal
# or
ln -s hie-bios.yaml hie.yaml  # if all else fails

The project's dependencies must be installed before starting the language server:

stack build --test --bench --only-dependencies
# or
cabal build --enable-tests --enable-benchmarks --only-dependencies kore

Developing with Nix

We provide a

expression with a suitable development environment and a binary cache at The development environment is intended to be used with

When the

package description file changes, run:
# Requires Nix to be installed.

This script is also run by an automatic workflow.

We provide a

for running integration tests:
nix-build test.nix  # run all integration tests
nix-build test.nix --argstr test imp  # run the integration tests in test/imp
nix-shell test.nix  # enter a shell where we can run tests manually

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