Documentation for infix ∌ assembled from the following types:

language documentation Sets, bags, and mixes

From Sets, bags, and mixes

(Sets, bags, and mixes) infix ∌

Returns True if $a does not contain $b, else False. More information, Wikipedia definition.

language documentation Operators

From Operators

(Operators) infix ∌

multi sub infix:<∌>($a,$b --> Bool:D)

Non-membership operator.

Returns True if $a is not an element of $b. Equivalent to !(cont).

say (1,2,3) ∌ 4; # OUTPUT: «True␤» 
say (1,2,3) !(cont) 2; # OUTPUT: «False␤» 

∉ is codepoint U+220C (DOES NOT CONTAIN AS MEMBER).