CJT writes:

180 degrees out of phase is a different phase, mathematically.

I stand by what I said, particularly in the context of what you
snipped.

In the context of "phase" in electric power, you are in error. That
mathematics has a different sense of "phase" is irrelevant.

"A polyphase system must provide a defined direction of phase rotation, so
mirror image voltages do not count towards the phase order. A 3-wire system
with two phase conductors 180 degrees apart is still only single phase."

-- http://en.wikipedia.org/wiki/Polyphase_system