code: function equals(v1, v2) {
      if (!arraysEqual(v1.size(), v2.size())) return false;
      return Vector.cascadeReduce(Vector.zip(v1, v2, (e1, e2) => e1 === e2), (prev, next) => prev && next, true);
  }
docs: True if the v1 and v2 represent the same vectors (do not need to be the same instance).