haskell - A theorem prover / proof assistant supporting (multiple) subtyping / subclassing -

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in short, looking theorem prover underlying logic supports multiple subtyping / subclassing mechanism.( tried use isabelle, not seem provide first class support subtyping. see this )

i define couple of types among subclasses / subtypes of others. furthermore, each type might subtype of more 1 type. example:

type type b type c type e type f  c subtype of c subtype of b e , f subtypes of b

ps: editing question again more specific (because of complains being of-topic!): looking theorem prover / proof assistance in can define above structure in straight forward manner (not workarounds kindly described respectable answers here). if take types classes seems above subtypings easily formulated in c++! looking formal system / tool can define such subtyping structure there , can reason?

many thanks

pvs has traditionally emphasized "predicate subtyping" lot, system bit old-fashioned these days , has fallen behind other big players more active: coq, isabelle/hol, agda, other hols, acl2.

you did not make application clear. reckon of big systems applied problem, 1 way or other. formalization matter phrase problem in suitable way within given logical environment. logics not programming languages, have real power of mathematics. experience in particular logic, able great , amazing things did not expect @ first sight.

when choosing system, lists of particular low-level features not relevant. more important general style , culture of system, before make commitment. can compare learning foreign language. before spend months or years study collect features of grammar? don't think so.


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