Parameterized methods are relations

world open.
birth1:Birth[father -> jacob; mother -> rachel;
             child -> joseph; order -> 11].
birth2:Birth[father -> jacob; mother -> rachel;
             child -> benjamin; order -> 12].
?Father[childWith(?Mother) -> ?Child] <-
    ?Birth:Birth[father -> ?Father; mother -> ?Mother;
                 child -> ?Child].
?- jacob[childWith(rachel) -> ?Child].
expect true: jacob[childWith(rachel) -> joseph].

A birth is represented as an identified object with named roles. The rule projects these roles into a parameterized method: Jacob’s child with Rachel is Joseph or Benjamin. The query returns both children.

The parentheses belong to the method’s parameters. They do not invoke Python or execute an object method. A method result is stored or derived logical knowledge. The same method can relate an object and argument to several results.

Birth objects are useful when a relationship itself needs a date, order, source or uncertainty annotation. Give each observation a stable ID. FrameX can also use structured identifiers such as birth(parent, child), but this example uses explicit names to keep the evidence easy to inspect. Function terms do not execute external code; recursive term generation needs bounds.

Choosing a representation

Use a simple slot for a simple binary relationship. Use a method when an argument naturally selects a relation. Use a named relationship object when you need to attach evidence or several roles. Favor the representation students can explain without memorizing positional arguments.

Try it

Add a birth with a different mother. Query that method argument and predict why the existing query is unchanged.