Hi, Following on from my earlier *Merging modules* email, where I tried to simulate ontology merging with Haskell modules; http://article.gmane.org/gmane.comp.lang.haskell.cafe/64943 I *think* that the type of merging that I am attempting is difficult with modules so I gave classes a try. I did not get very far (see below). Perhaps I need a combination of type classes and modules. In fairness this is more of a specification task than a programming task and perhaps I am barking up the wrong tree. Any help appreciated. Regards, Pat ============================================== attempting an ontology merge with type classes For specification of requirement see http://article.gmane.org/gmane.comp.lang.haskell.cafe/64943 ============================================== -- Data types for COMMON data Woman = WomanC data Person = PersonC -- Additional data type for ONTOLOGY1 data Bank = BankC -- Additional data type for ONTOLOGY2 -- but how do I let type Bank have the same name in both classes and -- still be distinct (homonyms) in the merged class -- data Bank = BankC class COMMON a b where class (COMMON a b) => ONTOLOGY1 a b where class (COMMON a b) => ONTOLOGY2 a b where class (ONTOLOGY1 a b, ONTOLOGY2 a b) => MERGEDONTOLOGY a b where -- not really sure how to proceed from here instance COMMON Woman Person where