The category "<specific_vehicle_type-not_creatable>" can be expressed as follows:

<specific_vehicle_type-not_creatable>

<a_a_v>

<a_a_v-sing>

<hmmwv>

<hmmwv-sing>

<i_f_v_spec>

<i_f_v_spec-sing>

<tank_type>

<tank_type-sing>

<tank_type-sing> <tank>

<tank_type-sing> <tank-sing>