if let Some(following_nonterminals) = indirections.get(&elem) {
                    for &(other, idx, rule) in following_nonterminals.iter() {
                        if !result.contains_key(&other) { continue; }

                        let mut copy = HashSet::new();
                        let mut needs_next = false;
                        {   // Lifetimes woo
                            let other_first_set = result.get(&other).unwrap();
                            for &term in other_first_set.iter() {
                                match term {
                                    ProdElem::Epsilon   => needs_next = true,
                                    _                   => { copy.insert(term); }
                                }
                            }
                        }

                        if needs_next {
                            if idx < rule.len() - 1 && !following_nonterminals.contains(&(rule[idx+1], idx + 1, rule)) {
                                if Grammar::analyze_rule_for_first(rule, idx + 1, result.get_mut(&elem).unwrap(), indirections.get_mut(&elem).unwrap()) {
                                    dirty = true
                                }
                            } else if idx == rule.len() - 1 && !result.get(&elem).unwrap().contains(&ProdElem::Epsilon) {
                                result.get_mut(&elem).unwrap().insert(ProdElem::Epsilon);
                                dirty = true;
                            }
                        }

                        for &c in copy.iter() {
                            if !result.get_mut(&elem).unwrap().contains(&c) {
                                result.get_mut(&elem).unwrap().insert(c);
                                dirty = true;
                            }
                        }
                    }
                }