Applying Logical Knowledge

  Queries

You can query the dynamic database from the listener.

A query is specified with a goal pattern.

Syntactically - a goal is the same as a structure or atom (a structure with 0 arguments).
Semantically - a goal is a pattern to be matched against in-memory clauses (dynamic or static).

Unification is the name of the pattern-matching algorithm.

If the goal unifies with the head of a clause, then the query succeeds (true/yes); if not it fails (fail/no)

Backtracking is the name of the search algorithm used to find a clause head that unifies.

logicbase:

seats(727,100).
seats(747,300).

queries:

?- seats(727,100).
yes

?- seats(727,50).

no

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