~ — NOT / Without

Function. Ranks: 0 monadic, ∞ ∞ dyadic

~Y negates Booleans, pervasively.

~0 1               ⍝ $t $f

X~Y removes the major cells of X found among the major cells of Y, retaining order and repetitions. Uses tolerant matching.

1 2 1 3~2 4        ⍝ 1 1 3
"banana"~"an"       ⍝ "b"
[1 2⋄3 4⋄1 2]~[1 2⋄] ⍝ [3 4⋄]

Y must have rank 1 or more. So to remove one character, write it as a string. ' ' is a unit. " " is a one-item vector.

"a b c"~" "         ⍝ "abc"

Inverse

~⁻¹Y is ~Y.

~⁻¹1 0   ⍝ $f $t

Errors

• RANK: Y is a unit
• LENGTH: the major cells of X and Y differ in shape