In module Test§

See primary documentation in context for sub isnt

multi sub isnt(Mu $gotMu:U $expected$desc = '')
multi sub isnt(Mu $gotMu:D $expected$desc = '')

Marks a test as passed if $got and $expected are not equal using the same rules as is(). The function accepts an optional description of the test.

isnt pi3'The constant π is not equal to 3';
my Int $a = 23;
$a = Nil;
isnt $aNil'Nil should not survive being put in a container';