with its initial model. The free logic <span
 style="font-family: arial; font-style: italic;">log</span>
: <span style="font-family: arial; font-weight: bold;">Theory</span><small
 style="font-family: arial;"><sup>&#8869;</sup></small> &#8594; <span
 style="font-family: arial; font-weight: bold;">Logic</span> and
underlying theory <span style="font-family: arial; font-style: italic;">th</span>
: <span style="font-family: arial; font-weight: bold;">Logic</span> &#8594; <span
 style="font-family: arial; font-