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

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

If  ⎕ML≥2, Disclose 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.

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

      ⊃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