 logic
over a common mediating theory, a lifting operation from the context of
theories to the context of logics, is an essential sub-step of IFF
alignment.<br>
</p>
<p>When free logics are investigated with respect to the lax IFF notion
of satisfaction, there is a question about the relationship between
unary relation types (unary predicates) and entity types (sorts). The
IFF adopts a laissez-faire attitude: use the least constraints needed.
It defines its basic logic using the constraint that every unary
