In Prolog, program logic is expressed in terms of relations, and a computation is initiated by running a query over these relations. Relations … See more

A design pattern is a general reusable solution to a commonly occurring problem in software design. Some design patterns in Prolog are … See more

For programming in the large, Prolog provides a module system, which is in the ISO Standard. However, while most Prolog systems support structuring the code into modules, … See more

Prolog is a homoiconic language and provides many facilities for reflective programming (reflection). Its implicit execution strategy makes it possible to write a concise See more

In Prolog, loading code is referred to as consulting. Prolog can be used interactively by entering queries at the Prolog prompt ?-. If there is no solution, Prolog writes no. If a solution exists then it is printed. If there are multiple solutions to the query, then … See more

A higher-order predicate is a predicate that takes one or more other predicates as arguments. Although support for higher-order programming takes Prolog outside the domain of first-order logic, which does not allow quantification over predicates, ISO Prolog now … See more

There is a special notation called definite clause grammars (DCGs). A rule defined via -->/2 instead of :-/2 is expanded by the preprocessor (expand_term/2, a facility analogous to macros in other languages) according to a few straightforward rewriting rules, … See more