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 is not a superset nor equal to $b, else False. More information, Wikipedia definition.

language documentation Operators

From Operators

(Operators) infix ⊉

multi sub infix:<⊉>($a,$b --> Bool:D)

Not a superset of nor equal to operator.

Returns True if $a is not a superset of $b. Equivalent to !(>=).

say (1,2,3) ⊉ (2,3,1); # OUTPUT: «False␤» 
say (1,2,3) ⊉ (2,3); # OUTPUT: «False␤» 
say 4 !(>=) (1,2,3); # OUTPUT: «True␤» 

⊉ is codepoint U+2289 (NEITHER A SUPERSET OF OR EQUAL TO).