{"id":"permutation-ranked-check","version":"1.0.0","description":"Check exact stable ordinal ranks for decimal-string values and nulls, reporting the first source-index discrepancy.","supported_operations":["check rank vector","validate stable ordinal ranks","verify exact decimal ranking","audit claimed ranks","find first wrong rank","check null first ranking certificate"],"unsupported_operations":["return a computed rank vector","rank binary floating point values"],"semantics":["Decimal strings use grammar -?(0|[1-9][0-9]*)(.[0-9]+)? and exact mathematical comparison.","Null sorts first; numerical ties are broken by lower source index.","Ranks are zero-based ordinal positions and compared by ascending source index.","The claim is never repaired or returned as recomputed data."],"limits":{"max_items":4096,"max_input_bytes":262144,"max_output_bytes":1024},"pricing":{"status":"unpriced","charge_usd":null},"input_schema":{"type":"object","additionalProperties":false,"required":["source","claimed_ranks"],"properties":{"source":{"type":"array","items":{"type":["string","null"]},"maxItems":4096},"claimed_ranks":{"type":"array","items":{"type":"integer","minimum":0,"maximum":4096},"maxItems":4096}}},"output_schema":{"type":"object","additionalProperties":false,"required":["valid","reason","discrepancy","reference_version"],"properties":{"valid":{"type":"boolean"},"reason":{"type":["string","null"]},"discrepancy":{"type":["object","null"],"additionalProperties":false,"properties":{"path":{"type":"string"},"index":{"type":"integer","minimum":0,"maximum":4096},"expected":{"type":["string","number","boolean","null"]},"actual":{"type":["string","number","boolean","null"]}},"required":["path","index"]},"reference_version":{"type":"string","const":"Knuth TAOCP Vol. 1, 3rd ed., §1.2.5 (Permutations); ECMA-262 2026 §7.2.11 SameValueZero"}}},"examples":[{"input":{"source":["2.0",null,"2","-1"],"claimed_ranks":[2,0,3,1]},"output":{"valid":true,"reason":null,"discrepancy":null,"reference_version":"Knuth TAOCP Vol. 1, 3rd ed., §1.2.5 (Permutations); ECMA-262 2026 §7.2.11 SameValueZero"}},{"input":{"source":["10","2"],"claimed_ranks":[0,1]},"output":{"valid":false,"reason":"rank_mismatch","discrepancy":{"path":"/claimed_ranks/0","index":0,"expected":1,"actual":0},"reference_version":"Knuth TAOCP Vol. 1, 3rd ed., §1.2.5 (Permutations); ECMA-262 2026 §7.2.11 SameValueZero"}}],"execute_url":"/v1/tools/permutation-ranked-check/versions/1.0.0/execute"}