This simple integer scalar reports the identification number for the most recent event which occurred, caused by an APL action or by an interrupt or by the ⎕SIGNAL system function.  Its value in a clear workspace is 0.

Example

      ÷0
DOMAIN ERROR: Divide by zero
      ÷0
     ∧
      ⎕EN
11

See APL Error Messages

Note: ⎕SIGNAL can be used to reset the value of this system constant.