Add a no-self-loop rule to the very general VP < VP < other verb AUX rule in UniversalEnglishGrammaticalRelations. This doesn't change any trees in the PTB Train section, but does help the tag updater not hit false positives for the AUX rules UniversalDependencies/docs#717

Author: AngledLuffa

src/edu/stanford/nlp/trees/UniversalEnglishGrammaticalRelations.java

@@ -150,7 +150,7 @@ private UniversalEnglishGrammaticalRelations() {}
   public static final GrammaticalRelation AUX_MODIFIER =
     new GrammaticalRelation(Language.UniversalEnglish, "aux", "auxiliary",
         DEPENDENT, "VP|SQ|SINV|CONJP", tregexCompiler,
-        "VP < VP < (/^(?:MD|VB.*|AUXG?|POS)$/=target)",
+        "VP=root < VP < (/^(?:MD|VB.*|AUXG?|POS)$/=target) : (=root !<<# =target)",
         "SQ|SINV < (/^(?:VB|MD|AUX)/=target $++ /^(?:VP|ADJP)/)",
         // add handling of tricky VP fronting cases...
         "SINV < (VP=target < (/^(?:VB|AUX|POS)/=aux < " + beAuxiliaryRegex + ") $-- (VP < VBG))");