A Formal Proof of Strong Equivalence for a Grammar Conversion from LTAG to HPSG-style Naoki Yoshinaga author Yusuke Miyao author Jun’ichi Tsujii author 2002-05 text Proceedings of the Sixth International Workshop on Tree Adjoining Grammar and Related Frameworks (TAG+6) Robert Frank editor Association for Computational Linguistics Universitá di Venezia conference publication yoshinaga-etal-2002-formal https://aclanthology.org/W02-2227/ 2002-05 187 192