The rules that use the category "<vp-system_utterance-inf-gapsout_null-gapsin_null-unit>" are:

<action_description-inf-not_inv>

<np-gapsout_null-gapsin_null-unit-not_wh_or_dummy> <vp-system_utterance-inf-gapsout_null-gapsin_null-unit>

<np-gapsout_null-gapsin_null-unit-not_wh_or_gq_or_dummy> <vp-system_utterance-inf-gapsout_null-gapsin_null-unit>