Refal is an acronym for REcursive Functions ALgorithmic language. This is usually written in mixed case "Refal", and sometimes in all upper case "REFAL". It is a functional programming language used mainly by mathematicians, for pattern matching, symbol manipulation (symbolic data processing): string processing; computer languages: translation, analysis, metacomputation, etc.; artificial intelligence: theorem proving, natural languages, knowledge bases; computer algebra; scripting and prototyping. It originated in the Soviet Union, created by Valentin F. Turchin. Related websites often have text in English and Russian.