Hi Miranda,

How to calculate the sum of list of lists in Haskell?

What do you mean by this? What is the value of a list? If you mean sum the numbers such that [[1,2],[3,4]] = 1+2+3+4 then you are able to ask two alternative questions - how do i convert a list of lists to a list, and how do i sum a list. Both can be answered by Hoogle: http://haskell.org/hoogle/?q=%5BInt%5D%20-%3E%20Int The list of lists to a list is a bit easier so I'll leave you to solve that one :) Thanks Neil

Miranda Kajtazi wrote:

Help,

How to calculate the sum of list of lists in Haskell?

Do you mean something of the form Num a => [[a]] -> a ? If so, this should do it: Prelude> let foo = sum . concat Prelude> foo [[1,2,3],[4,5]] 15 Cheers, Maxime