{"id":"permutation-indices-check","version":"1.0.0","description":"Check whether claimed indices are exactly one occurrence of every source index, reporting the first discrepancy.","supported_operations":["check index permutation","validate claimed permutation indices","detect duplicate permutation index","find first missing permutation index","verify index rearrangement","audit permutation certificate"],"unsupported_operations":["compute a sorting permutation","repair invalid indices"],"semantics":["A valid claim contains each source index exactly once.","Claim positions are scanned left to right; then missing source indices are scanned ascending.","Source scalars, including null and duplicates, affect only the required length.","The claim is never repaired or replaced."],"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_indices"],"properties":{"source":{"type":"array","items":{"type":["string","number","boolean","null"]},"maxItems":4096},"claimed_indices":{"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":["a","b","c"],"claimed_indices":[2,0,1]},"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":["a","b","c"],"claimed_indices":[0,0,2]},"output":{"valid":false,"reason":"duplicate_index","discrepancy":{"path":"/claimed_indices/1","index":1,"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-indices-check/versions/1.0.0/execute"}