static LS ai_turnCertainWordsIntoUniqueDollarVars(Set<S> wordsToTransform, LS tok) {
  MultiSet<S> ms = ciMultiSet();
  ret mapWithIndex(tok, (t, i) ->
    odd(i) && contains(wordsToTransform, t) ? "$" + t + emptyIfOne(ms.add(t)) : t);
}

sS ai_turnCertainWordsIntoUniqueDollarVars(Set<S> wordsToTransform, S s) {
  ret join(ai_turnCertainWordsIntoUniqueDollarVars(wordsToTransform, javaTokWithBrackets(s)));
}