nx_rans_gate.nx

nx_rans_gate.nx -- SOVEREIGN liar-kill gate for nx_rans (the patent-free rANS entropy keystone). Proves ENTIRELY within Nishi (no python, no 3rd party): for an entropy stage whose encoder AND decoder we both own, lossless round-trip IS the complete correctness criterion. T1 round-trip bit-exact on a skewed 3-symbol buffer (decode(encode(x)) == x) T2 it actually COMPRESSES (enc < raw) -- honest entropy coding, not a memcpy T3 round-trip bit-exact on a 64-symbol buffer (full pipeline over a wide alphabet) T4 degenerate single-symbol round-trip + near-zero output (entropy-correct: 0 bits/sym -> 4-byte state) T5 determinism: re-encoding the same input yields byte-identical output T6 LIAR-KILL: a CORRUPTED stream does NOT reproduce the input -- the decoder genuinely depends on the bitstream, so the gate cannot pass by echoing GREEN iff 6/6. Durable knowledge/status/rans_gate.log. license_tier: ORIGINAL