Let&#39;s say for arguments sake I want to make a new finer grained numeric class hierarchy. But, I also want to have the following occur:<div><br></div><div>(1) Existing modules which have defined data types which have Num instances can be used with functions in my new hierarchy</div><div>(2) New data types defined in the new hierarchy automatically get Num instances if appropriate so they can be used in existing modules.</div><div><br></div><div>I know this is somewhat of a vague question but roughly how would I go about this?<span></span></div><div><br></div><br>