Veer and Turn <M/4> x <N/4>

This must be preceded by a call that sets up a natural veering direction. There is no default direction.

Veer Left or Right in the appropriate direction. Then the Centers Cast Off by the first fraction, while the ends turn the second number of quarters, starting with a turn inward.

\phBB{b1s,b2n,g2s,g3n}	\phfour{b2e,b1n,g3s,g2w}

before Veer and Turn 1/2 x 1/4, after right-handed Recycle	after