~
~Y negates Booleans, pervasively.
~Y
~0 1 ⍝ 1x 0x
X~Y removes items found in Y, retaining order and repetitions. Uses tolerant membership.
X~Y
Y
1 2 1 3~2 ⍝ 1 1 3 'banana'~'an' ⍝ ,'b'