flex Expert System Toolkit - LPIS

8. Run-Time Interpretation of KSL 116
Actions
Relations
0 ).
Actions are represented directly by the corresponding Prolog clause. In
addition, the name of the action is remembered as a clause of
relation/2.
Example
action empty_into( X, Y ) ;
do Y`s contents := Y`s contents + X`s contents
and X`s contents := 0 .
will be represented by the Prolog clauses
relation( empty_into, 2 ) .
empty_into( X, Y ) :-
new_value( @(contents,Y), @(contents,Y) +
@(contents,X) ),
new_value( @(contents,X), 0 ) .
Relations are represented directly by the corresponding Prolog clause. In
addition, the name of the relation is remembered as the relation
relation/2.
Example
Functions
relation sister( X, Y )
if father( X ) = father( Y )
and not male( Y )
and X is not equal to Y .
will be represented by the Prolog clauses
relation(sister,2) .
sister(X,Y) :-
equality(father(X),father(Y)),
not male(Y),
not equality(X,Y) .
Functions are represented by instances of the relation function/3, as
follows.
function( Function, Arguments,Value ).
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