anchor.diff:                          for family in children.other do
                               handle family
           res.ToArray()
  -    
  +
  +    let leftSide = ref _leftSide
  +    let numToString = ref _numToString
  +
       let checkFamilyIsGivenNonterminal nonterminalInd (family : Family) = 
  -        match leftSide with 
  +        match !leftSide with 
           | None -> failwith "leftSide is not specified"
           | Some ls -> nonterminalInd = ls.[family.prod]
   
  
positive.code:         | Some ind -> ind
  
      let getNonterminalStringByProd prod =
          match numToString with
          | None -> failwith "numToString is not specified"
          | Some nts ->
              match leftSide with 
              | None -> failwith "leftSide is not specified"
              | Some ls -> nts <| ls.[prod]
  
  
negative.code:         | true -> arr.[0]
  
      let getNonterminalIndex nonterminal =
          match !numToString with
          | None -> failwith "numToString is not specified"
          | Some nts ->
              match !leftSide with 
              | None -> failwith "leftSide is not specified"
              | Some ls -> ls |> Array.tryFind (fun x -> String.Equals (nts x, nonterminal))
  
  