Rolling
<anything>
Previous
Previous
Up
Next
Next
Roll, and then
finish
the
<anything>
call. All of the "ing" calls (Flowing, Rolling, etc.) apply some action to the preceding call, and then let that action replace the first part of the "anything" call.
\phfour{b1n,g1s,g2n,b2s}
\phBB{g1s,b2n,b1s,g2n}
\phBB{g1w,b2e,b1w,g2e}
\phfour{g2s,b1n,b2s,g1n}
1
1
2
2
1
2
1
2
1
2
1
2
2
1
2
1
before Recycle
before Rolling Contour the Line
after Roll
finished