Bool[Map[K, V:Bool]]

class MapBool[K, V](implicit ev: Bool[V]) extends Bool[Map[K, V]] with Serializable {
  def one = Map.empty[K, V].withDefaultValue(ev.one)
  def or(a: Map[K, V], b: Map[K, V]) = {
    val ad = a.withDefaultValue(ev.zero)
    val bd = b.withDefaultValue(ev.zero)
    (a.keySet ++ b.keySet).map(k => k -> ev.or(ad(k), bd(k))).toMap
  }

  def complement(a: Map[K, V]) = a.mapValues(ev.complement)
  def and(a: Map[K, V], b: Map[K, V]) =
    (a.keySet intersect b.keySet).map(k => k -> ev.and(a(k), b(k))).toMap
  def zero = Map.empty[K, V].withDefaultValue(ev.zero)
}