!!


Vocabulary
logic

Variable description
The cut operator. Use the cut operator to suppress backtracking.

Examples
In the following example, it is used to define that cats generally eat mice, but Tom does not.
USING: logic prettyprint ; IN: scratchpad LOGIC-PREDS: is-ao consumeso ; LOGIC-VARS: X Y ; SYMBOLS: Tom Jerry Nibbles mouse cat milk cheese fresh-milk Emmentaler ; { { is-ao Tom cat } { is-ao Jerry mouse } { is-ao Nibbles mouse } { is-ao fresh-milk milk } { is-ao Emmentaler cheese } } facts { consumeso X milk } { { is-ao X mouse } ;; { is-ao X cat } } rule { consumeso X cheese } { is-ao X mouse } rule { consumeso Tom mouse } { !! f } rule { consumeso X mouse } { is-ao X cat } rule { { consumeso Tom X } { is-ao Y X } } query .
{ H{ { X milk } { Y fresh-milk } } }


Definition