Absys was an early declarative

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 ...

from the

University of Aberdeen The University of Aberdeen (abbreviated ''Aberd.'' in List of post-nominal letters (United Kingdom), post-nominals; ) is a public university, public research university in Aberdeen, Scotland. It was founded in 1495 when William Elphinstone, Bis ...

. It anticipated a number of features of

Prolog Prolog is a logic programming language that has its origins in artificial intelligence, automated theorem proving, and computational linguistics. Prolog has its roots in first-order logic, a formal logic. Unlike many other programming language ...

such as

negation as failure Negation as failure (NAF, for short) is a non-monotonic inference rule in logic programming, used to derive \mathrm~p (i.e. that p is assumed not to hold) from failure to derive p. Note that \mathrm ~p can be different from the statement \neg p o ...

, aggregation operators, the central role of backtracking and constraint solving. Absys was the first implementation of a logic programming language. The name ''Absys'' was chosen as an abbreviation for ''Aberdeen System''.

References

*"ABSYS: An Incremental Compiler for Assertions", J.M. Foster et al., Mach Intell 4, Edinburgh U Press, 1969, pp. 423–429 {{DEFAULTSORT:Absys Declarative programming languages Prolog programming language family Academic programming languages Logic programming languages Programming languages created in 1967

See also

References