Unifying Recursive and Co-recursive Definitions in Sheaf Categories.

Pietro Di Gianantonio Marino Miculan Unifying Recursive and Co-recursive Definitions in Sheaf Categories. 136-150 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2987&spage=136 2004 conf/fossacs/2004 FoSSaCS db/conf/fossacs/fossacs2004.html#GianantonioM04