k-Valued Non-Associative Lambek Categorial Grammars are not Learnable from Strings.

Denis Béchet Annie Foret k-Valued Non-Associative Lambek Categorial Grammars are not Learnable from Strings. 351-358 2003 ACL http://acl.ldc.upenn.edu/acl2003/main/pdfs/Bechet.pdf db/conf/acl/acl2003.html#BechetF03