Multiple boxing
In Programming forum the question was posed
What is the verb foo such that foo 1 1 2 2 3 3 4 2 3 4 4 1 2 2 2 1 +---+---------------------------+-+-------+-+ |1 1|+---+---------+-+---------+|1|+-----+|1| | ||2 2|+---+---+|2|+-+-----+|| ||2 2 2|| | | || ||3 3|+-+|| ||3|+---+||| |+-----+| | | || || ||4||| || ||4 4|||| | | | | || || |+-+|| || |+---+||| | | | | || |+---+---+| |+-+-----+|| | | | | |+---+---------+-+---------+| | | | +---+---------------------------+-+-------+-+ ?