implement AUX for elliptical do/have/be

  * see UniversalDependencies/UD_English-EWT#403

_build/utils/upos.ini

@@ -120,3 +120,10 @@ xpos=/WRB/&upos!=/X/&func!=/goeswith/	none	#1:upos=ADV
 xpos=/WRB/&func=/mark/	none	#1:func=advmod
 ; fixed expression preposition or complementizer with xpos RB for first token should have upos ADV ('morphological' POS)
 xpos=/RB/&upos!=/PART/;func=/fixed/	#1.#2	#1:upos=ADV
+
+; UD 2.13
+; AUX pos for be, have, do without object (excl. "there is" and possible zero relatives for "things we do/VERB")
+lemma=/be/&upos=/VERB/;xpos=/EX/	#1>#2	#1:storage=has_expl
+lemma=/be/&upos=/VERB/&storage!=/has_expl/	none	#1:upos=AUX
+lemma=/do|have/&upos=/VERB/;func=/obj|ccomp|.*:pass/	#1>#2	#1:storage=has_obj
+lemma=/do|have/&upos=/VERB/&storage!=/has_obj/&func!=/.*:relcl/	none	#1:upos=AUX