A sublanguage is a

subset In mathematics, a Set (mathematics), set ''A'' is a subset of a set ''B'' if all Element (mathematics), elements of ''A'' are also elements of ''B''; ''B'' is then a superset of ''A''. It is possible for ''A'' and ''B'' to be equal; if they a ...

of a

language Language is a structured system of communication that consists of grammar and vocabulary. It is the primary means by which humans convey meaning, both in spoken and signed language, signed forms, and may also be conveyed through writing syste ...

. Sublanguages occur in

natural language A natural language or ordinary language is a language that occurs naturally in a human community by a process of use, repetition, and change. It can take different forms, typically either a spoken language or a sign language. Natural languages ...

, computer

programming language A programming language is a system of notation for writing computer programs. Programming languages are described in terms of their Syntax (programming languages), syntax (form) and semantics (computer science), semantics (meaning), usually def ...

, and

relational database A relational database (RDB) is a database based on the relational model of data, as proposed by E. F. Codd in 1970. A Relational Database Management System (RDBMS) is a type of database management system that stores data in a structured for ...

In natural language

informatics Informatics is the study of computational systems. According to the Association for Computing Machinery, ACM Europe Council and Informatics Europe, informatics is synonymous with computer science and computing as a profession, in which the centra ...

natural language processing Natural language processing (NLP) is a subfield of computer science and especially artificial intelligence. It is primarily concerned with providing computers with the ability to process data encoded in natural language and is thus closely related ...

, and

machine translation Machine translation is use of computational techniques to translate text or speech from one language to another, including the contextual, idiomatic and pragmatic nuances of both languages. Early approaches were mostly rule-based or statisti ...

, a sublanguage is the language of a restricted domain, particularly a technical domain. In mathematical terms, "a subset of the sentences of a language forms a sublanguage of that language if it is closed under some operations of the language: e.g., if when two members of a subset are operated on, as by ''and'' or ''because'', the resultant is also a member of that subset". This is a specific term for what in most linguistic study is referred to a language variety or register.

In computer languages

The term sublanguage has also sometimes been used to denote a computer language that is a subset of another language. A sublanguage may be restricted syntactically (it accepts a subgrammar of the original language), and/or semantically (the set of possible outcomes for any given program is a subset of the possible outcomes in the original language).

Examples

For instance, ALGOL 68S was a subset of

ALGOL 68 ALGOL 68 (short for ''Algorithmic Language 1968'') is an imperative programming language member of the ALGOL family that was conceived as a successor to the ALGOL 60 language, designed with the goal of a much wider scope of application and ...

designed to make it possible to write a single-pass

compiler In computing, a compiler is a computer program that Translator (computing), translates computer code written in one programming language (the ''source'' language) into another language (the ''target'' language). The name "compiler" is primaril ...

for this ''sublanguage''.

SQL Structured Query Language (SQL) (pronounced ''S-Q-L''; or alternatively as "sequel") is a domain-specific language used to manage data, especially in a relational database management system (RDBMS). It is particularly useful in handling s ...

(Structured Query Language) statements are classified in various ways, which can be grouped into sublanguages, commonly: a data query language (DQL), a

data definition language In the context of SQL, data definition or data description language (DDL) is a syntax for creating and modifying database objects such as tables, indices, and users. DDL statements are similar to a computer programming language for defining d ...

(DDL), a data control language (DCL), and a

data manipulation language A data manipulation language (DML) is a computer programming language used for adding (inserting), deleting, and modifying (updating) data in a database. A DML is often a sublanguage of a broader database language such as SQL, with the DML com ...

(DML).

In relational database theory

theory, the term "sublanguage", first used for this purpose by

E. F. Codd Edgar Frank "Ted" Codd (19 August 1923 – 18 April 2003) was a British computer scientist who, while working for IBM, invented the relational model for database management, the theoretical basis for relational databases and relational database ...

in 1970, refers to a

computer language A computer language is a formal language used to communicate with a computer. Types of computer languages include: * Software construction#Construction languages, Construction language – all forms of communication by which a human can Comput ...

used to define or manipulate the structure and contents of a

relational database management system A relational database (RDB) is a database based on the relational model of data, as proposed by E. F. Codd in 1970. A Relational Database Management System (RDBMS) is a type of database management system that stores data in a structured for ...

(RDBMS). Typical sublanguages associated with modern RDBMS's are QBE (Query by Example) and

(Structured Query Language). In 1985, Codd encapsulated his thinking in twelve rules which every database must satisfy in order to be truly relational. The fifth rule is known as the ''Comprehensive data sublanguage rule'', and states: : ''A relational system may support several languages and various modes of terminal use (for example, the fill-in-the-blanks mode). However, there must be at least one language whose statements are expressible, per some well-defined syntax, as character strings, and that is comprehensive in supporting all of the following items:'' :* ''Data definition'' :* ''View definition'' :* ''Data manipulation (interactive and by program)'' :* ''Integrity constraints'' :* ''Authorization'' :* ''Transaction boundaries (begin, commit, and rollback)''

References

{{Reflist Relational model Language