I do know that I could express my algorithms via list-comprehension or in a List Monad, all using tuples. And that would be concrete and grossly inefficient. You should probably tell us what these algorithms accomplish, rather
Günther Schmidt wrote: than how one implementation goes. From a higher-level view of what you're trying to do [but not as high as saying 'implement abstract relational algebra'], it will be easier to give concrete advice.
So how would it be possible to express selecting /field/ b from /record/ x and field c from record y, creating record z, while making sure that record x does have field b and record y does have field c? I mean design a syntax for it? Perhaps you should tell us why you think you need records at all, and record sub-typing to boot. You might well be right, but the higher-level requirements will have a much bigger influence on the design than anything else.
Jacques