struct TrieNode * root = getNode(); 
struct TrieNode * sub_root = getNode();
// i:
    // s1
    insert(sub_root, "1", 0, rule_0);
        // s2, b, restore point
        insert(rule_0, "2", 1, rule_1);
            // C
                // s3
                insert(rule_1, "3", 2, rule_2);
                // s5
                insert(rule_2, "5", 3, rule_3); // link to next statement, which happens to be a definition
            // C
                // s2, restore point
                insert(rule_0, "2", 1, rule_4);
                // s8
                insert(rule_4, "8", 2, rule_5);
                // s5
                insert(rule_5, "5", 3, rule_3); // link to next statement, which happens to be a definition
        // e
        // s9, b, restore point, because that this is directly after a previous branch the restore point is set to the start of this branch
            // C
                // s9
                insert(rule_3, "9", 2, rule_4);
                // s1
                insert(rule_4, "1", 3, rule_5); // link to end
            // C
                // s9, restore point
                insert(rule_3, "9", 2, rule_6);
                // s9
                insert(rule_6, "9", 2, rule_7);
                // s2
                insert(rule_7, "2", 3, rule_5); // link to end
        // s6, end of rule
        insert(rule_5, "6", 2, NULL);