%% davar_yatza.pl — Rules 9-11: Exception from a general rule.
%%
%% Rule 9: Davar shehayah biklal veyatza min haklal l'lamed —
%%   Something that was in the general and was singled out
%%   to teach: it teaches about the entire general, not just itself.
%%
%% Rule 10: Davar shehayah biklal veyatza liton to'an echad —
%%   Singled out to teach the same type of law: reduces the severity
%%   of the general for that type.
%%
%% Rule 11: Davar shehayah biklal veyatza liton to'an acher —
%%   Singled out to teach a different type of law: the exception
%%   follows both the general's rules AND its own new rules.

:- module(davar_yatza, [
    davar_yatza_llamed/3,
    davar_yatza_toan_echad/3,
    davar_yatza_toan_acher/3
]).

%% ============================================================
%% RULE 9: EXCEPTION TEACHES ABOUT THE GENERAL
%% ============================================================

%% davar_yatza_llamed(Exception, General, Teaching)
%% The exception teaches about ALL members of the general.

davar_yatza_llamed(
    exception(ExceptionItem, Law),
    general(GeneralCategory),
    teaches(Law, applies_to_all(GeneralCategory))
).

%% Example: The chatat offering has specific blood-sprinkling rules.
%% These rules teach about ALL offerings, not just chatat.
davar_yatza_llamed(
    exception(chatat, blood_sprinkling_north),
    general(all_offerings),
    teaches(blood_sprinkling_north, applies_to_all(all_offerings))
).

%% ============================================================
%% RULE 10: EXCEPTION WITH SAME TYPE OF LAW
%% ============================================================

%% davar_yatza_toan_echad(Exception, General, Modification)
%% Same type of law but singled out = reduces severity for the general.

davar_yatza_toan_echad(
    exception(ExceptionItem, SameLaw),
    general(GeneralCategory, SameLaw),
    reduces(SameLaw, for(GeneralCategory), because(ExceptionItem))
).

%% ============================================================
%% RULE 11: EXCEPTION WITH DIFFERENT TYPE OF LAW
%% ============================================================

%% davar_yatza_toan_acher(Exception, General, DualApplication)
%% Different type of law = exception follows both sets of rules.

davar_yatza_toan_acher(
    exception(ExceptionItem, NewLaw),
    general(GeneralCategory, OriginalLaw),
    dual_rules(ExceptionItem, follows(OriginalLaw), and(NewLaw))
).

%% Example: Metzora singled out from tumah laws with unique procedures.
%% Metzora follows both general tumah laws AND metzora-specific laws.
davar_yatza_toan_acher(
    exception(metzora, outside_camp_procedure),
    general(tumah, standard_purification),
    dual_rules(metzora, follows(standard_purification), and(outside_camp_procedure))
).