L.S., Consider the module definition: // module Infinite where x = 1 : map (+1) x y = 1 : map (+1) y \\ and the following session // Hugs session for: C:\hugs98\lib\Prelude.hs D:\TopFolder\Haskexper\Misc\Infinite.hs Type :? for help Infinite> take 5 x [1,2,3,4,5] Infinite> take 5 x == take 5 y True Infinite> x == y ERROR - Garbage collection fails to reclaim sufficient space Infinite> take 5 x == take 5 y True ERROR - Garbage collection fails to reclaim sufficient space Infinite> \\ The first evaluation of take 5 x == take 5 y causes no problems, but after the stack overflow caused by evaluating x == y the second evaluation of take 5 x == take 5 y returns the correct answer but also an error message. Please let me know (i) whether this should be expected, (ii) if so, why, (iii) if not, how this can be corrected. Regards, Raymond Boute