Given a sentence and two mentions from the text (arguments), indicate a phrase (a verb or noun phrase) that describes the relationship between the provided arguments.

Sentence: 'Paper presented at the 7th International Conference on Head-Driven Phrase Structure Grammar , held on July 22-23 , 2000 as part of the Berkeley Formal Grammar Conference 2000 .', Argument/Subject 1: 'paper', Argument/Subject 2: 'conference'
present at