static L<Map<S, Lisp>> matchConditions_all(L<Lisp> conditions) {
  ret matchConditions_all(conditions, new HashMap);
}

static L<Map<S, Lisp>> matchConditions_all(L<Lisp> conditions, Map<S, Lisp> m) {
  if (empty(conditions)) ret ll(m);
  
  Lisp condition = first(conditions);
  L<Map<S, Lisp>> candidates = matchCondition_all(condition, m);
  if (empty(candidates)) ret candidates; // first condition failed
  
  new LinkedHashSet<Map<S, Lisp>> results;
  for (Map<S, Lisp> m2 : candidates)
    results.addAll(matchConditions_all(dropFirst(conditions), m2));
  ret asList(results);
}

Began life as a copy of #1008124