[MaxGhenis]

Adds 23 companion cases to uk/regulations/uksi/2013/376/{22,27,29}.test.yaml: claimant-only LCWRA and work-allowance inputs, the reg 29(4) joint-claimant parenthetical, and reg 29(2)'s limits on two carer elements. No module bytes change.

Why now

PolicyEngine/policyengine-uk#1989 changes LCWRA, carer elements and work-allowance eligibility to use the claimants' circumstances. These cases establish the existing atomic RuleSpec behavior independently from PolicyEngine. The ProgramSpec carer composition and benefit-cap receipt/entitlement scopes are queued separately; this PR does not claim those integration paths are correct.

Hand-computed expectations

The expectations come from UC Regs 2013 reg 27, reg 29, reg 22, and reg 36's table, using the revised CLML fetched 2026-10-01. WRA 2012 s 40 defines “claimant” as a single claimant or each of joint claimants. All households are synthetic.

The period conventions match the existing files: 2026-04 for regs 22 and 27; a custom one-day period, 2026-04-06 through 2026-04-06, for reg 29's Day judgments. The £429.80 case supplies the reg 36 amount for a pre-2026 claimant in the 2026-27 regime; it is not a test of a historical assessment period or of upstream rate selection.

Reg 27: one LCWRA element, claimant slots only

The only asserted output is universal_credit_award_lcwra_element_included_amount. The reg 36 amounts are explicit test inputs. Reg 27(1)-(2) includes the qualifying claimant's amount; (4)(a)-(b) permits one element and selects the higher amount when both qualify.

New case	Hand computation	Expected monthly amount
joint_claimants_both_lcwra_at_same_amount_include_one_element	One element: max(217.26, 217.26)	217.26
joint_claimants_both_lcwra_include_one_higher_amount_when_first_is_higher	One element: max(429.80, 217.26)	429.80
joint_claimants_only_first_has_lcwra_include_first_amount	First qualifies: 217.26; second's 429.80 is inapplicable	217.26
joint_claim_with_neither_lcwra_ignores_single_claimant_slot	Neither joint claimant qualifies: 0; single slot is inapplicable	0
single_claimant_pre_2026_lcwra_includes_higher_regulation_36_amount	Qualifying single claimant's supplied amount: 429.80	429.80
single_claim_ignores_joint_claimant_lcwra_slots	Single claimant does not qualify: 0; joint slots are inapplicable	0

Reg 29: LCWRA priority and the joint-claimant exception

Reg 29's atomic module exposes inclusion judgments; its monetary output is deferred (29.yaml:9). These cases assert those judgments, not a monetary amount. The first six assert claimant_carer_element_included; the last three assert both_joint_claimants_carer_elements_included.

New case	Law-derived expectation	Expected
joint_claimant_carer_with_lcwra_keeps_carer_element_when_lcwra_element_is_included_for_other_claimant	Reg 29(4)'s parenthetical exception applies: the LCWRA element is included for the other joint claimant; other inclusion conditions hold	holds
joint_claimant_carer_with_lcwra_has_lcwra_element_only_when_not_included_for_other_claimant	Same carer, but exception fails: only LCWRA may be included for this claimant	not_holds
single_claimant_carer_with_lcwra_has_lcwra_element_only_even_if_other_claimant_slot_is_set	Single claim: joint-claimant exception is inapplicable; only LCWRA	not_holds
joint_claimant_carer_without_lcwra_keeps_carer_element_when_other_claimant_has_lcwra_element	Claimant has no LCWRA, so (4) does not displace their carer element	holds
joint_claimant_not_elected_for_same_severely_disabled_person_has_no_carer_element	Reg 29(3): this claimant is neither the sole relevant carer nor the elected/determined carer	not_holds
claimant_without_regular_and_substantial_caring_responsibilities_has_no_carer_element	Reg 29(1)'s caring condition fails	not_holds
joint_claimants_caring_for_same_severely_disabled_person_not_both_included	Reg 29(2): caring for the same person prevents both elements	not_holds
joint_claimants_not_both_included_when_only_one_qualifies	Reg 29(2): both must qualify; only one does	not_holds
single_claim_never_includes_two_carer_elements	Reg 29(2) applies only to joint claimants	not_holds

Reg 22: limited capability alone gives the work allowance

Reg 22(1)(b) gives a work allowance for claimant LCW even without a child. Under (2), the allowance is £710 without a housing costs element and £427 with one. The earned deduction is 0.55 × max(0, E − allowance), or 0.55 × E when neither condition is met. The total deduction adds U under (1)(a). Reg 22(3) uses the joint-claimant calculation for a couple member claiming as a single person.

The table shows every asserted output: effective joint-claimant judgment (J), work-allowance judgment (WA), earned_income_for_deduction (E), unearned_income_for_deduction (U), applicable_work_allowance_amount (A), earned_income_amount_subject_to_taper (T), earned_income_deduction_from_maximum_amount (D), and universal_credit_award_deduction_from_maximum_amount (total).

New case	J / WA	E / U / A (£)	Hand computation T → D → total (£)
joint_claimants_without_child_one_with_lcw_higher_work_allowance_without_housing_costs	holds / holds	1500 / 120 / 710	1500 − 710 = 790; 790 × .55 = 434.50; 120 + 434.50 = 554.50
joint_claimants_without_child_one_with_lcw_lower_work_allowance_with_housing_costs	holds / holds	1500 / 120 / 427	1500 − 427 = 1073; 1073 × .55 = 590.15; 120 + 590.15 = 710.15
single_claimant_with_lcw_and_no_child_higher_work_allowance_without_housing_costs	not_holds / holds	2000 / 0 / 710	2000 − 710 = 1290; 1290 × .55 = 709.50; 0 + 709.50 = 709.50
single_claimant_with_lcw_and_no_child_lower_work_allowance_with_housing_costs	not_holds / holds	900 / 0 / 427	900 − 427 = 473; 473 × .55 = 260.15; 0 + 260.15 = 260.15
single_claimant_without_child_or_lcw_has_no_work_allowance_with_housing_costs	not_holds / not_holds	800 / 50 / 0	800 − 0 = 800; 800 × .55 = 440; 50 + 440 = 490
joint_claimants_without_child_or_lcw_have_no_work_allowance	holds / not_holds	1200 / 0 / 0	1200 − 0 = 1200; 1200 × .55 = 660; 0 + 660 = 660
single_claim_ignores_joint_claimant_child_and_lcw_slots	not_holds / not_holds	1000 / 0 / 0	Joint slots are inapplicable; 1000 × .55 = 550; 0 + 550 = 550
member_of_couple_claiming_as_single_with_partner_lcw_uses_joint_work_allowance	holds / holds	1000 / 0 / 710	Reg 22(3) applies; 1000 − 710 = 290; 290 × .55 = 159.50; 0 + 159.50 = 159.50

Verification

Unsigned local python -m axiom_encode.cli test at current-main CI pins: axiom-encode c326d1ac0acdb557f047a3054160b19dd72602fa; axiom-rules-engine 05eac9d2f89dabe5c6673176260762cef3a58f47, built from the exact pinned source in scratch. All three runs return success: true and empty failure lists.

File	Existing	New	Passed
22.test.yaml	4	8	12/12
27.test.yaml	4	6	10/10
29.test.yaml	4	9	13/13
Total	12	23	35/35

Repository pytest tests -p no:cacheprovider: 26 passed, 2 skipped. git diff --check passes. Saved JSON logs, the reproducible runner, pinned-source metadata and the engine-build log are in a local scratch checkout; the completion report records their exact paths. These are synthetic companion tests; no paid encode, signing, oracle or survey-data run was made.

CI: Repository Checks is green and terminal: validate / shards, validate / validate (uk) and validate / validate passed; drift-alarm was skipped as expected on a pull request. Background gh pr checks --watch exited 0. The PR is ready for review and remains unmerged.

Scope

This follows the test-only companion pattern of #391. The atomic modules use claimant-specific slots (27.yaml:43, 22.yaml:151); reg 29(4)'s parenthetical is present (29.yaml:42). The tests establish these paths as encoded-correct for parity, conditional on correctly projected claimant inputs. They do not establish which members an upstream runtime places in those slots.

Queued separately: #404 covers claimant-only ProgramSpec carer composition and independent oracle projections; the scope comment on #389 covers reg 83 receipt/entitlement limbs. The atomic tests here do not close either queue.

🤖 Generated with Claude Code

Verification at the merged head (2026-10-12)

The verification links above describe the original 2026-10-01 head. Before merging, main was merged in (head faad423a). CI is green at that head, and an independent review re-checked all 23 expectations against the regulations: reg 22's 2026-04-06 table, reg 27, reg 29 and the reg 36 amounts. It confirmed that only the three companion files change.

[MaxGhenis]

Merged by the Axiom engineering hub at faad423 with --merge. Gates: gh pr checks exit 0; MERGEABLE; not draft. Reviewed head: faad423. Independent GPT-6.1 Sol review: APPROVE_WITH_NITS; all 23 companion expectations match UC Regs 2013 regs 22, 27, 29 and 36; no module changes. Body nits addressed.