code: public final Ix<Boolean> sequenceEqual(Iterable<? extends T> other, IxPredicate2<? super T, ? super T> comparer) {
          return new IxSequenceEqual<T>(this, nullCheck(other, "other is null"), nullCheck(comparer, "comparer is null"));
      }
docs: Determines if two sequences have the same elements in the same order and are the same length based
  on the given comparer's boolean value.
  <p>
  The result's iterator() doesn't support remove().
  @param other the other sequence to compare with
  @param comparer the predicate receiving elements from this and the other sequence and returns true if those
  elements are equal
  @return the new Ix instance
  @throws NullPointerException if other is null
  @since 1.0