=:= ( quot: ( env -- n m ) -- goal )

Vocabulary

logic

Inputs

quot	a quotation

Outputs

goal	a logic-goal

Word description

The quotations takes an environment and returns two values. =:= returns the internal representation of the goal which returns t if values returned by the quotation are same numbers. =:= is intended to be used in a quotation. If there is a quotation in the definition of rule, logic uses the internal definition of the goal obtained by calling it.

See also

(==), =\=

Definition

USING: accessors combinators formatting kernel logic.private
math ;

IN: logic

:: =:= ( quot: ( env -- n m ) -- goal )
    quot collect-logic-vars :> args quot "[ %u =:= ]" sprintf
    <pred> :> =:=-pred =:=-pred args logic-goal boa :> =:=-goal 
    V{
        {
            =:=-goal
            [| env |
                env quot ( env -- n m ) call-effect 2dup
                [ number? ] both? [ = ] [ 2drop f ] if
            ]
        }
    } =:=-pred defs<< =:=-goal ;