The rules that use the vocabulary item "is" are:

<zoom_operation>

where is <zoomable_thing>

<speed_mod>

march rate is <speed>

speed is <speed>

<attach_detach_unit_verb>

is opcon to

<catch_up_speed_mod>

catch up is <speed>

catch up speed is <speed>

<attach_detach_unit_verb-report_to>

is opcon to

<commander_phrase>

this is <commander>

<repair_command>

<repair_verb-not_located> <other_unit> tow vehicle is <other_unit-controlled_unit>

<create_operation>

<coordinates-sing> is <point_name>

<point_name> is <coordinates>

<point_name> is at <coordinates>

<system_operation>

<h_hour> is <time_point_name>

<h_hour> is now