Hello Benjamin,
[Float] is a list of floats. (Float) is not.
thanks for pointing out an error. But now I get an other error message. integriereListe::[Float]->[Float]->[Float] integriereListe [][] = 0.0 integriereListe (x:xs) (y:ys) = (y - y2) / 2.0 * (x2 -x) where x2 = head xs y2 = head ys No instance for (Fractional [Float]) arising from a use of `/' Possible fix: add an instance declaration for (Fractional [Float]) In the first argument of `(*)', namely `(y - y2) / 2.0' In the expression: (y - y2) / 2.0 * (x2 - x) In an equation for `integriereListe': integriereListe (x : xs) (y : ys) = (y - y2) / 2.0 * (x2 - x) where x2 = head xs y2 = head ys Thomas