by clicking on the Tools link in the left corner of the top frame. Click on the "Assert" link in the column on the left. Enter " <tt><span style="font-size: xx-small;">(isa Peter DomesticPet)</span></tt> " in the large text box. Click on the Cyclify button immediately above the large text box. Click the Assert Formula button.</span></p>
<p style="font-family: Arial, sans-serif; font-size: medium; line-height: normal;">You can now try asserting that Billy and Peter are siblings, using the predicate <tt><s