Vincent Simonet Type Inference with Structural Subtyping: A Faithful Formalization of an Efficient Constraint Solver. 283-302 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2895&spage=283 2003 conf/aplas/2003 APLAS db/conf/aplas/aplas2003.html#Simonet03