The category "<vp-base-gapsout_null-gapsin_null-unit>" can be expressed as follows:

<vp-base-gapsout_null-gapsin_null-unit>

<adv> <vp-base-not_mod-gapsout_null-gapsin_null-unit>

<unit_command-discourse_all-gapsout_null-gapsin_null> <conj> <unit_command-discourse_all-gapsout_null-gapsin_null>

<unit_command-gapsout_null-gapsin_null>

<unit_command-system_utterance-gapsout_null-gapsin_null> <conj> <unit_command-system_utterance-gapsout_null-gapsin_null>

<unit_command-user_response-gapsout_null-gapsin_null> <conj> <unit_command-user_response-gapsout_null-gapsin_null>