| Up Arrow | ↑ | 
If ⎕ML<2 Mix
      ↑ 'Hip' 'Hop'
Hip
Hop
      ↑ (6 4) 5 3
6 4
5 0
3 0
      ↑[0.5] 'Hip' 'Hop'
HH
io
pp
        If ⎕ML≥2 First
↑ (6 4) 5 3 6 4
      4 ↑ 'Pineapple'
Pine
      ¯5 ↑ 'Pineapple'
apple
      mat
1  2  3  4
5  6  7  8
9 10 11 12
      
      2 ¯3 ↑ mat
2 3 4
6 7 8
      ¯2 ↑ mat
5  6  7  8
9 10 11 12
      ¯2 3 ↑ 7
0 0 0
7 0 0