 style="font-style: italic; font-weight: bold;">f</span>) :
<span style="font-family: arial; font-style: italic;">expr</span>(<span
 style="font-weight: bold; font-style: italic;">L</span>) &#8594; <span
 style="font-family: arial; font-style: italic;">expr</span>(<span
 style="font-style: italic; font-weight: bold;">&#321;</span>) maps an
expression of the source language to an
expression of the target language. This also is axiomatized in the
language namespace. The IFF transforms formal concepts in terms