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What is it?

Brachylog is a declarative logic programming language much like Prolog. Brachylog is designed to be much terser than Prolog, while retaining some readability.

Currently in development.

Brachylog uses SWI-Prolog as Prolog engine.

How do I use this?


Check out Brachylog's Wiki if you want to learn how to write programs in this language.

You may want to watch this short video introduction to Brachylog.

Try it online!

You can try out Brachylog on Try it online!, thanks to @DennisMitchell.

Brachylog language bar

You can find here the Brachylog language bar which gives you access to all symbols used in Brachylog on any webpage (by clicking on the symbols or by inputing shortcuts), thanks to @abrudz.

The interpreter

Brachylog's interpreter is entirely written in Prolog. Therefore, installing SWI-Prolog (version 7 and up) is mandatory to use Brachylog (We do not guarantee that Brachylog's interpreter will be compatible with any other Prolog implementation).

To run Brachylog's interpreter, start SWI-Prolog's interpreter inside the src directory available in this repository, and consult the file (consult(brachylog).). Alternatively, you can run the interpreter with:

$ swipl src/

You can then run Brachylog programs using different predicates:

  • run_from_file(FileName, Input, Output): FileName is an atom (i.e. between single quotes ') representing the file containing your Brachylog code. For example: run_from_file('code.brachylog',"Test Input",Z).

  • run_from_atom(Code, Input, Output): Code is an atom (i.e. between single quotes ') containing your Brachylog code. For example: run_from_atom('∧"Hello, World!"w',_,_). Note that you will have to escape certain characters in Code.

  • run(Input, Output): This will run a Brachylog program that has already been transpiled to Prolog using either of the two previous predicates. More precisely, this will query brachylog_main/2 in the file

The first two predicates will transpile your Brachylog program into Prolog, subsequently generating a file called in the same directory that contains The three run predicates will then consult it and query brachylog_main/3.

Note that the first two run predicates also exist with either no Output argument, or with no Input nor Output argument, if necessary. For example, run_from_file('code.brachylog') is equivalent to run_from_file('code.brachylog', _, _).