Pattern matching, implict par. question

Hello, When trying type CTPar = ([Double],Int,Int) ctPar ::(?ctPar::CTPar)=>CTPar ctPar@(us,n,j) = ?ctPar I got this error message in ghci is: " Illegal overloaded type signature(s) in a binding group for ctPar, us, n, j that falls under the monomorphism restriction When generalising the type(s) for ctPar, us, n, j Failed, modules loaded: CrossTypeOps." Should the monomorphis restriction really apply here? The values of us,j,n do depend on the context, but not their types (right?). J.A.