X must be a scalar or vector.  R is a vector of the elements of X excluding those elements which occur in Y taken in the order in which they occur in X.

Elements of X and Y are considered the same if X≡Y returns 1 for those elements.

⎕CT and ⎕DCT are implicit arguments of Excluding. Excluding is also known as Without.

Examples

      'HELLO'~'GOODBYE'
HLL
      'MONDAY' 'TUESDAY' 'WEDNESDAY'~'TUESDAY' 'FRIDAY'
 MONDAY  WEDNESDAY
 
      5 10 15~⍳10
15

For performance information, see Search Functions and Hash Tables.