This requires the dancers to imagine that they have just completed some call
that had people collide and take right hands. Some or all of the people will
be in right-handed miniwaves. Those people imagine that they are on the same
spot, as they would have been at the instant of the collision. They do
their part of the common spot call from that compressed virtual setup.
This concept is sometimes used when the miniwaves are left-handed.
This concept is sometimes called "Common Point", "Common End", or
something similar, indicating who should be considered to have collided.
\sxvbigdiamonds{b4e,g2w,b1s,.+.,.+.,g3s}
\sxvdiamonds{g1e,b4s,b1w,g2s}
before Common Point Diamonds Exchange the Diamonds 1/4