Bill MacCartney Trond Grenager Marie-Catherine de Marneffe Daniel Cer Christopher D. Manning Learning to recognize features of valid textual entailments. 2006 conf/naacl/2006 HLT-NAACL http://acl.ldc.upenn.edu/N/N06/N06-1006.pdf db/conf/naacl/naacl2006.html#MacCartneyGMCM06