It's not about combining, it's about being designed as a construction based on other known patterns. See http://conwaylife.com/wiki/Gemini http://conwaylife.com

It's not about combining, it's about being designed as a construction based on other known patterns. See http://conwaylife.com/wiki/Gemini http://conwaylife.com/wiki/Gemini for an example of a non-elementary ship.