# Contract (F5-conf-01)
- Question: Walrasian equilibrium of a 2-agent 2-good Cobb-Douglas exchange economy, good 2 numeraire.
- Estimands: p = p1/p2 (closed form), allocation x1_A,x2_A,x1_B,x2_B, z1 at p (should be 0), Walras residual p z1 + z2 (should be 0), numerical root of z1(p) as independent check.
- Assumptions: 0<alpha_i<1, strictly positive endowments (=> positive incomes, interior demands), p2=1 normalisation; equilibrium unique for Cobb-Douglas (gross substitutes).
- Outputs: out/results.json (keys per TASK.md table), out/report.md (6 sections), out/analysis.py, out/claims.json; plus protocol files under out/state and out/exclusions.csv.
- Info rules: only data/; numerical check must root-find z1(p), not evaluate closed form; list every data issue in data_issues.
- Invalidity: non-positive endowments/alpha outside (0,1); inconsistent aggregate endowments that cannot be reconciled.