Hello I got this line in the profile output: COST CENTRE MODULE no. entries %time %alloc %time %alloc ticks bytes addDeduction L42s.Maths.Prover.Base 22730 2362045 1.1 4.6 52.3 52.6 81 614808848 And it seems that "addDeduction" has been called 2 362 045 times ? But from other (personal) log files this function should be called less than 10 000 times. I wonder if the laziness of haskell can grow the "entries" field which is defined by: "The number of times this particular point in the call tree was entered.", but what "enter" means for ghc is a question for me. Thank you for answering -- Emmanuel Chantréau http://www.maretmanu.org/emmanuel/