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

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

<aux-vform_inf-vform_subcat_base> <vp-system_utterance-base-gapsout_null-gapsin_null-unit>

<action_description-system_utterance-fin-inv>

<aux-vform_fin-vform_subcat_base> <np-gapsout_null-gapsin_null-unit-not_wh_or_dummy> <vp-system_utterance-base-gapsout_null-gapsin_null-unit>

<aux-vform_fin-vform_subcat_base> <np-gapsout_null-gapsin_null-unit-not_wh_or_gq_or_dummy> <vp-system_utterance-base-gapsout_null-gapsin_null-unit>

<action_description-base-not_inv>

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

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

<vp-system_utterance-fin-gapsout_null-gapsin_null-unit>

<aux-vform_fin-vform_subcat_base> <vp-system_utterance-base-gapsout_null-gapsin_null-unit>