On 20/12/11 10:16, Patrick Browne wrote:

Hi, I am trying to implement a set of 4 modules that blend the action of a monk moving up a mountain on day 1 and returning down by the same path on day 2 [1][2]. The code should reflect the fact that there is some time and place which is common to the two days where the monk would *meets himself*. My Haskell code is based on a Maude version[3][4]. Only 3 times and places are considered in the code; start, meet, and end called 1,2, and 3 (e.g. the start time for the upward journey is timeu1). Using qualified elements, I can get the meets function to give the correct results, but I cannot get the location function to work. Is it possible the get meets to work without qualification? Any suggestions in getting location to work?

Regards, Pat

I think you need to rethink the solution: Haskell is not a logic programming language. You definitely don't need the type class, and you don't need instances. Paul.