def kn_sub
import bend-ml-bpe-tokenizer@0.1.3.0/main.bend as BendMlBpeTokenizerimport Base
419# if x == a and x is known, a is known too
420def kn_sub(+D: List<&2, Rule>, +x: Tk, +a: Tk, ex: {x == a : Tk}, kx: {True{} == kn(D, x) : Bool}) -> {True{} == kn(D, a) : Bool}:
421 %ex : {True{} == kn(D, _) : Bool}
422 kx