This could be defined in a geometrically accurate way as Invert the Column 1/2,
then the ends Counter Rotate while the centers Reset 1/4 and 2/3 Recycle.
But a more useful definition starts with Invert the Column 3/4. Then,
of the outer columns of 3, the first 2 continue Counter Rotate to
become ends of lines, while the last one moves forward to be in a line
with the very centers, and that line does a 2/3 Recycle.
\sxvlines{b3s,g3s,b4s,g4s}
\sxvBBBs{g4n,...,b4n,b3s,g3n,...}
\sxvdiamonds{b4w,g3n,g2e,b3s}
\sxvlines{b4w,b3w,g1e,g2e}
Start
Invert 3/4
first 2 Counter Rotate, last one steps ahead
finished
The person left behind on the Invert (the original #4) must wait patiently for
the last of the 3 people walking past, before doing the 2/3 Recycle. Don't grab
the wrong person.
On a Cross Replace the Column, use a Cross Invert 3/4 and a 2/3 Cross Cycle.
\sxvlines{b3s,g3s,b4s,g4s}
\sxvBBBs{g1s,...,b2s,b3s,g2s,...}
\sxvdiamonds{g3e,g1s,b2w,b3s}
\sxvlines{g4e,g3e,b1w,b2w}
Start
Cross Invert 3/4
first 2 Counter Rotate, last one steps ahead
finished
If "but <anything>" is used, that call replaces the 2/3 Recycle or 2/3 Cross Cycle.