ily: arial; font-style: italic;">cloth</span>(<span
 style="font-style: italic; font-weight: bold;">&#321;</span>) maps a closed
theory of the
source language to a closed theory of the target language. It is
defined in terms of the direct image expression function <big><span
 style="font-family: script mt bold;">P</span></big><span
 style="font-family: arial; font-style: italic;">expr</span>(<span
 style="font-weight: bold; font-style: italic;">f</span>) : <big><span
 style="font-family: script mt bold;">P<