anchor.diff:      | ParsedInput.ImplFile input -> walkImplFileInput input
   
   let getWrittenCases (matchExpr: MatchExpr) =
  -    let trueForAll pred list =
  -        List.exists (pred >> not) list = false
  -
       let rec checkPattern pat =
           match pat with
           | SynPat.Const(_const, _) -> false
  
positive.code: 
  let tryGetRangeBetweenWithAndFirstClause (matchExpr: MatchExpr) =
      maybe {
          let! fstClause =
              match matchExpr.Clauses with
              | hd :: _ -> Some hd
              | _ -> None
  
          return unionRanges matchExpr.MatchWithRange.EndRange fstClause.Range.StartRange
      }
  
  
negative.code:                 |> List.unzip
                  |> (fun (_, pat) -> pat)
  
              if List.forall checkPattern patList then
                  Some (func())
              else
                  None
  