b
= b
{scope}
The <shape of minimum-cost positive-weight ternary prefix trees> arguments in ii–vi assume a <full-support finite distribution>: $p_i>0$ for every retained source symbol. The printed setup does not state this globally. Each affected solution gives the proof with that qualification and a counterexample when zero-probability symbols are allowed in arbitrary redundant <code trees>. Part i needs no such qualification.