Hi, When compiling this: ************ import Complex; complex_root :: (Float, Float, Float) -> (Complex Float, Complex Float) complex_root (a,b,c) = (x1,x2) where { delta = b * b - 4 * a * c :: Float; sqr_delta = if delta >= 0 then (sqrt delta) :+ 0 else 0 :+ (sqrt delta) :: (Complex Float); x1 = (b + sqr_delta)/(2 * a); x2 = (b - sqr_delta)/(2 * a); } *********** I get this error message: ********** Couldn't match `Float' against `Complex Float' Expected type: Float Inferred type: Complex Float In the second argument of `(+)', namely `sqr_delta' In the definition of `x1': x1 = (b + sqr_delta) *********** Can you help me finding what is wrong? Shouldn't "b" be converted to Complex Float and be summed to sqr_delta? Thanks for your help, Maurício