implement main
    open core

    % facts
    class facts - parentDB
        parent : (string Parent, string Children).

    % is parent
    class predicates
        is_parent: (string Parent, string Children) nondeterm (i,i).
    clauses
        is_parent(Parent, Children) :-
            parent(Parent, Children).

    % get children
    class predicates
        get_children: (string Parent, string Children) nondeterm (i,o).
    clauses
        get_children(Parent, Children) :-
            parent(Parent, Children).

    % get parent
    class predicates
        get_parent: (string Children, string Parent) nondeterm (i,o).
    clauses
        get_parent(Children, Parent) :-
            parent(Parent, Children).

    % print all
    class predicates
        print_all: (string*, string*) nondeterm.
    clauses
        print_all([], []).
        print_all([HParent|TParent], [HChildren|TChildren]) :-
            stdio::writef("Родитель: %, ребёнок: %\n", HParent, HChildren),
            print_all(TParent, TChildren).

    % queries
    class predicates
        query_marina_sasha: ().
        query_aleksey_olga: ().
        query_nikolai_children: ().
        query_ivan_parent: ().
        query_print_all: ().
    clauses
        query_marina_sasha() :-
            is_parent("Марина", "Саша"),
            !,
            stdio::write("Марина родитель Саши\n")
            ;
            stdio::write("Марина НЕ родитель Саши\n").
        query_aleksey_olga() :-
            is_parent("Алексей", "Ольга"),
            !,
            stdio::write("Алексей родитель Ольги\n")
            ;
            stdio::write("Алексей НЕ родитель Ольги\n").
        query_nikolai_children() :-
            get_children("Николай", Children),
            !,
            stdio::writef("% - ребёнок Николая\n", Children)
            ;
            stdio::write("У Николая нет детей\n").
        query_ivan_parent() :-
            get_parent("Иван", Parent),
            !,
            stdio::writef("% - родитель Ивана\n", Parent)
            ;
            stdio::write("У Ивана нет родителей\n").
        query_print_all() :-
            LParent = [Children || parent(_, Children)],
            LChildren = [Parent || parent(Parent, _)],
            print_all(LParent, LChildren),
            !;
            succeed().

    % data
    clauses
        parent("Илья", "Марина").
        parent("Марина", "Ира").
        parent("Елена", "Иван").
        parent("Николай", "Ира").
        parent("Ольга", "Алексей").
        parent("Марина", "Саша").
        parent("Сергей", "Иван").

    % main
    clauses
        run() :-
            console::init(),

            stdio::write("\nЗапрос №1:\n"),
            query_marina_sasha(),

            stdio::write("\nЗапрос №2:\n"),
            query_aleksey_olga(),

            stdio::write("\nЗапрос №3:\n"),
            query_nikolai_children(),

            stdio::write("\nЗапрос №4:\n"),
            query_ivan_parent(),

            stdio::write("\nЗапрос №5:\n"),
            query_print_all().


end implement main

goal
    mainExe::run(main::run).