In Natural Language

In Informatics

Informatics (academic field)

Informatics is the science of information, the practice of information processing, and the engineering of information systems. Informatics studies the structure, algorithms, behavior, and interactions of natural and artificial systems that store, process, access and communicate information...

, natural language processing

Natural language processing

Natural language processing is a field of computer science and linguistics concerned with the interactions between computers and human languages; it began as a branch of artificial intelligence....

, and machine translation

Machine translation

Machine translation, sometimes referred to by the abbreviation MT is a sub-field of computational linguistics that investigates the use of computer software to translate text or speech from one natural language to another.On a basic...

, 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" (Z.S. Harris Language and Information, Columbia U. Press, 1988, p. 34).

In Computer Languages

The term sublanguage has also sometimes been used to denote a computer language that is a subset of another language. For instance, ALGOL 68S

ALGOL 68S

ALGOL 68S was designed as a subset of ALGOL 68 in order to permit single-pass compilation. It was mostly for numerical computation.-Implementations:...

 was a subset of ALGOL 68

ALGOL 68

ALGOL 68 isan imperative computerprogramming language that was conceived as a successor to theALGOL 60 programming language, designed with the goal of a...

 designed to make it possible to write a single-pass compiler

Compiler

A compiler is a computer program that transforms source code written in a programming language into another computer language...

 for this sublanguage. 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).

In Relational Database Theory

In relational database

Relational database

A relational database is a database that conforms to relational model theory. The software used in a relational database is called a relational database management system . Colloquial use of the term "relational database" may refer to the RDBMS software, or the relational database itself...

 theory, the term sublanguage, first used for this purpose by E. F. Codd

Edgar F. Codd

Edgar Frank "Ted" Codd was an English computer scientist who, while working for IBM, invented the relational model for database management, the theoretical basis for relational databases...

 in 1970, refers to a computer language used to define or manipulate the structure and contents of a relational database management system

Relational database management system

A relational database management system is a database management system that is based on the relational model as introduced by E. F. Codd. Most popular databases currently in use are based on the relational database model....

 (RDBMS). Typical sublanguages associated with modern RDBMS's are QBE

Query by Example

Query by Example is a database query language for relational databases. It was devised by Moshé M. Zloof at IBM Research during the mid 1970s, in parallel to the development of SQL. It is the first graphical query language, using visual tables where the user would enter commands, example elements...

 (Query by Example) and SQL

SQL

SQL is a programming language designed for managing data in relational database management systems ....

(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)