:- module('subset',[]).

en("the target language is: prolog.

the templates are:
    *a set* is a subset of *a set*,
    *a thing* is a set,
    *a thing* belongs to *a set*.

the knowledge base sets includes:

a set A is a subset of a set B
    if A is a set
    and B is a set
    and for all cases in which  
        a thing belongs to A
        it is the case that
        the thing belongs to B.

scenario facts is:
    family one is a set.
    family two is a set.
   
    Bob belongs to family one.
    Alice belongs to family one.
   
    Alice belongs to family two.
   
query subset is:
    which set is a subset of which other set.
   
scenario lists is:
    [Alice, Bob] is a set.
    [Alice] is a set.

    a thing belongs to a set
        if the thing is in the set.
").

/** <examples>
?- answer subset with facts.
?- answer subset with lists.
?- show prolog.
*/