From Generalized Columns.
Ends 
  Mirror 
  Turn To A Line 
  ('Turn & Deal' toward Promenade direction)
  as Centers do a Leads U-Turn Back (by turning toward the Left),
  Veer Right, and As Couples Extend.
Ends in Parallel Lines.
 
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Alternative definition (this is the original definition!):
  - Ends
 
  - 1/4 To Promenade, Step Ahead, Turn another 1/4
      toward their initial turning direction, and adjust to
      end in Parallel Lines.
 
  - Centers
 
  - 1/4 To Promenade, Step Ahead,
      1/4 To Promenade, and Step Ahead (to become Leaders in
      Parallel Lines).
 
Single Polly Wally [C3A]:
 From a 1 x 4 Column.  
  Outsides Mirror Single Turn To A Line as Centers
  Left Roll To A Wave and Extend.  
  Ends in a 2 x 2.
 
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 |  before Single Polly Wally |   | after
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