Split a term’s meaning by the act’s purpose

Intent

I want to apply a definition only in an explicitly named domain.

A domain is not transferred by a matching word.

Correct formFrozen execution sceneBoundary

Wrong form and why it stays silent

Incorrect form

definition eligible(p: Person) exact { when young(p); for_purposes_of Tax; }

The for_purposes_of shorthand is rejected with E0201. The executable domain in the example is an ordinary scope formula; it constrains both halves of exact.

Correct form

Arxo Law

language "law.core" version "0.2";
package recipes.g.r06 version "0.1.0";
namespace "urn:recipe:g-concepts:06";

entity Person;
relation young(p: Person) kind empirical;
enum Purpose { Tax; Civil; }
relation purpose(p: Person, purpose: Purpose);
definition eligible(p: Person) exact {
    when young(p);
    scope purpose(p, Tax);
}

Frozen execution scene

Facts on 13.09.2026	Question	Answer
tax purpose	truth(eligible(entity_ref("urn:recipe:g-concepts:06:p")))	truth_status == TRUE_ONLY; / COMPUTED
civil purpose	truth(eligible(entity_ref("urn:recipe:g-concepts:06:p")))	truth_status == NEITHER; / COMPUTED
purpose not named	truth(eligible(entity_ref("urn:recipe:g-concepts:06:p")))	truth_status == NEITHER; / COMPUTED
scope removed	truth(eligible(entity_ref("urn:recipe:g-concepts:06:p")))	truth_status == TRUE_ONLY; / COMPUTED

tax purpose qualifies

Arxo Law

test "tax purpose qualifies" {
    given {
        context {
            legal_time @2026-09-13;
            decision_time @2026-09-13T09:00:00+05:00;
            knowledge_time @2026-09-13T09:00:00+05:00;
            timezone "Asia/Almaty";
        }
        assert young(entity_ref("urn:recipe:g-concepts:06:p")); assert purpose(entity_ref("urn:recipe:g-concepts:06:p"), Tax);
    }
    evaluate truth(eligible(entity_ref("urn:recipe:g-concepts:06:p")));
    expect truth_status == TRUE_ONLY;
    expect evaluation_status == COMPUTED;
}

civil purpose stays unknown

Arxo Law

test "civil purpose stays unknown" {
    given {
        context {
            legal_time @2026-09-13;
            decision_time @2026-09-13T09:00:00+05:00;
            knowledge_time @2026-09-13T09:00:00+05:00;
            timezone "Asia/Almaty";
        }
        assert young(entity_ref("urn:recipe:g-concepts:06:p")); assert purpose(entity_ref("urn:recipe:g-concepts:06:p"), Civil);
    }
    evaluate truth(eligible(entity_ref("urn:recipe:g-concepts:06:p")));
    expect truth_status == NEITHER;
    expect evaluation_status == COMPUTED;
}

unnamed purpose stays unknown

Arxo Law

test "unnamed purpose stays unknown" {
    given {
        context {
            legal_time @2026-09-13;
            decision_time @2026-09-13T09:00:00+05:00;
            knowledge_time @2026-09-13T09:00:00+05:00;
            timezone "Asia/Almaty";
        }
        assert young(entity_ref("urn:recipe:g-concepts:06:p"));
    }
    evaluate truth(eligible(entity_ref("urn:recipe:g-concepts:06:p")));
    expect truth_status == NEITHER;
    expect evaluation_status == COMPUTED;
}

removed scope restores unqualified reading

Arxo Law

test "removed scope restores unqualified reading" {
    given {
        context {
            legal_time @2026-09-13;
            decision_time @2026-09-13T09:00:00+05:00;
            knowledge_time @2026-09-13T09:00:00+05:00;
            timezone "Asia/Almaty";
        }
        assert young(entity_ref("urn:recipe:g-concepts:06:p")); assert purpose(entity_ref("urn:recipe:g-concepts:06:p"), Civil);
    }
    evaluate truth(eligible(entity_ref("urn:recipe:g-concepts:06:p")));
    expect truth_status == TRUE_ONLY;
    expect evaluation_status == COMPUTED;
}

Counterfactual

Mutation scope purpose(p, Tax); → for_purposes_of Tax;: LDC-E0201.

Boundary

Purpose is a synthetic case input, not a built-in choice of legal order. Two independent acts must have their own symbols and domains. Imported enum members require qualification — see Distinguish an enum member from a data variant.