static L<SS> ai_texts_dollarAny(S a, S b, S c) {
  if (isDollarVar(b)) todo();
  bool va = isDollarVar(a), vc = isDollarVar(c);
  new L<SS> l;
  
  // no vars
  if (!va && !vc) {
    if (has(a, b, c)) l.add(emptyMap());
    ret l;
  }
  
  // var on the left
  if (va && !vc) {
    for (S s : ai_texts("$X", b, c))
      l.add(litmap(a, s));
    ret l;
  }
  
  // var on the right
  if (vc && !va) {
    for (S s : ai_texts(a, b, "$X"))
      l.add(litmap(c, s));
    ret l;
  }
  
  // vars on both sides
  for (WebRelation r : indexedRelations(b))
    addIfNotNull(l, strictlitmapOrNull(a, web_text(r.a), c, web_text(r.b)));
  ret l;
}

static L<SS> ai_texts_dollarAny(T3<S> t) {
  ret ai_texts_dollarAny(t.a, t.b, t.c);
}

Began life as a copy of #1012112