From Parallel Columns of {n},
  where n is greater than or equal to 3.
The First n dancers (where n corresponds to the given 
  fraction, see first note below) as a unit Trail Off to end in 
  Concentric Columns of n as the remaining dancers, using Circulates, 
  move forward to form a compact formation.
Notes:
- 
From Parallel Columns of 4, n=1 for 1/4;
    2 for 1/2; 3 for 3/4; or 4 (full) if no fraction is given.
- 
From Parallel Columns of 3, n=1 for 1/3;
    2 for 2/3; or 3 (full) if no fraction is given.
- 
On a full Cross Invert The Column, everyone does the
    Trail Off movement but must also slide together upon completion of the call 
    to form adjacent Columns.  Do not slide together if call is
    fractionalized (e.g., 3/4 Cross Invert The Column ends
    in an "H").
| |   |  | before Cross Invert The Column
 |  |  |  |   |  |   |  |   |  |   |  | after 1/4
 |  | after 1/2
 |  | after 3/4
 |  | (done) | 
 | 
Variation:Magic Cross Invert The Column fraction [C2V].
 See also Invert The Column (fraction) [C2].