The rules that use the category "<unit_command-system_utterance-gapsout_null-gapsin_pp_gap>" are:

<basic_nl_command-system_utterance-gapsout_null-gapsin_pp_gap>

<unit-not_gesture-gapsout_pp_gap-gapsin_pp_gap-sing> <unit_command-system_utterance-gapsout_null-gapsin_pp_gap>