This schematic represents three switches to control the load. It's actually not three "3-way" switches. It's two 3-way switches and one 4-way switch. The 4-way switch is represented in the diagram as two 3-way switches. In reality, when the center switch is flipped, you must change the position of both because it's a double-pole, double-throw switch which this software doesn't offer as an option.
