First (⎕ML) R←⊃Y or R←↑Y

The symbol chosen to represent First depends on the current Migration Level.

If ⎕ML<2, First is represented by the symbol: ⊃.

If ⎕ML≥2, First is represented by the symbol: ↑.

Y may be any array. R is an array. If Y is non-empty, R is the value of the first item of Y taken in ravel order. If Y is empty, R is the prototype of Y.

First is the inverse of Enclose. The identity R←→⊃⊂R holds for all R. First is also referred to as Disclose.

Examples

      ⊃1
1

      ⊃2 4 6
2

      ⊃'MONDAY' 'TUESDAY'
MONDAY

      ⊃(1 (2 3))(4 (5 6))
1  2 3

      ⊃⍳0
0

      ' '=⊃''
1

      ⊃1↓⊂1,⊂2 3
0  0 0