More strict symetricity?

[jkuchar]

$_equals($one, $other) || $_equals($other, $one) is that correct?

Isn't better to have:

\assert($_equals($one, $other) === $_equals($other, $one), 'not symmetric, when a->b is in relation, b->a must also be in relation')
return $one === $other || $_equals($one, $other) || array compare(..);