Left Shoe ⊂
Monadic Left Shoe means
1(2 3)
┌─┬───┐
│1│2 3│
└─┴───┘
⊂ 1(2 3)
┌───────┐
│┌─┬───┐│
││1│2 3││
│└─┴───┘│
└───────┘
⊂⊂ 1(2 3)
┌─────────┐
│┌───────┐│
││┌─┬───┐││
│││1│2 3│││
││└─┴───┘││
│└───────┘│
└─────────┘
Dyadic Left Shoe means
If ⎕ML<3
Partitioned Enclose
0 1 0 1 ⊂ 1 2 3 4
┌───┬─┐
│2 3│4│
└───┴─┘
If ⎕ML≥3
Partition
0 1 0 1 ⊂ 1 2 3 4
┌─┬─┐
│2│4│
└─┴─┘