!747
!multi-line strings

m {
  !include #1001509 // rules & statements
  
  p {
    rules.add([["$1 is the singular of $2." <=> "$2 is the plural of $1."]]);
    statements.add("house is the singular of houses.");
    
    process();
    print(fromLines(statements));

    ask([[how many plurals does "house" have?]]);
    ask([[what are the plurals of "house"?]]);
  }
  
  static void ask(S q) {
    print("? " + q);
    
    new Map<S, S> map;
    if (match4("how many plurals does $1 have?", q, map))
      print("  => " + getPlurals(map.get("$1")).size());
    else if (match4("what are the plurals of $1?", q, map))
      print("  => " + structure(getPlurals(map.get("$1"))));
    else
      print("dunno.");
  }
  
  static L<S> getPlurals(S x) {
    S c = "$2 is the plural of " + x;
    print("[" + c + "]");
    MultiMap<S, S> matches = matchAll(c);
    ret matches.get("$2");
  }
}