Arend is a theorem prover and a programming language based on Homotopy Type Theory.

• For more information about the Arend language, visit arend-lang.github.io or the documentation.
• For instructions on building Arend locally, general description of the codebase, there's ARCHITECTURE.md.
• For community forums, checkout this link.
• For editing Arend code, we suggest IntelliJ Arend (instructions).
• The standard library of Arend is here. It serves as a math library.

You can find release version of Arend binary (a jar file named "Arend.jar") in the release page. The Arend jar can be used to typecheck a library:

$ java -jar Arend.jar [path-to-library]

You can also start a REPL:

$ java -jar Arend.jar -i

If you start the REPL at the root directory of a library, the REPL will load the library. For more information and usage about command line usage of Arend, please refer to --help:

$ java -jar Arend.jar -h

Arend is under active development, so you may expect to depend your project on a development version of Arend, either a certain git revision or the SNAPSHOT version. This is possible via JitPack, simply add this to your build.gradle:

repositories {
    maven { url 'https://jitpack.io' }
}
dependencies {
    // The version of Arend -- can be a short revision, "[branch]-SNAPSHOT",
    // "-SNAPSHOT", or a tag (or a release, like "v1.4.0").
    String arendVersion = "master-SNAPSHOT"
    // Open API for writing Arend extensions
    implementation "com.github.JetBrains.Arend:api:$arendVersion"
    // The generated ANTLR parser
    implementation "com.github.JetBrains.Arend:parser:$arendVersion"
    // The generated protobuf classes
    implementation "com.github.JetBrains.Arend:proto:$arendVersion"
    // The main compiler
    implementation "com.github.JetBrains.Arend:base:$arendVersion"
}

In case you prefer Gradle Kotlin DSL, use the following syntax in your build.gradle.kts:

repositories {
    maven("https://jitpack.io")
}
dependencies {
    // The version of Arend
    val arendVersion = "master-SNAPSHOT"
    implementation("com.github.JetBrains.Arend:api:$arendVersion")
    implementation("com.github.JetBrains.Arend:parser:$arendVersion")
    implementation("com.github.JetBrains.Arend:proto:$arendVersion")
    implementation("com.github.JetBrains.Arend:base:$arendVersion")
}