Doubling the Front
Bringer-up (man in blue) moves forward to his left (or right) to stand alongside the File Leader of the original file and the Half-File Leader (in red) falls in behind that man (in blue) to stand beside who has become the last man of the first file (second man in gray). But what if the file has more than four soldiers? See how a longer file does this doubling by clicking 'Advance' below.
Reduction of that doubling