Bottom Clause

Synonyms

Saturation; Starting clause

Definition

The bottom clause is a notion from the field of inductive logic programming. It is used to refer to the most specific hypothesis covering a particular example when learning from entailment. When learning from entailment, a hypothesis H covers an example e relative to the background theory B if and only if B ∧ H ⊨ e, that is, B together with Hentails the example e. The bottom clause is now the most specific clause satisfying this relationship w.r.t the background theory B and a given example e.

For instance, given the background theory B

bird :- blackbird.

bird :- ostrich.

and the example e:

flies :- blackbird, normal.

the bottom clause is H

flies :- bird, blackbird, normal.

The bottom clause can be used to constrain the search for clauses covering the given example because all clauses covering the example relative to the background theory should be more general than the bottom clause. The bottom clause can be computed using inverse...