anchor.diff:          let mutable innerState = innerState
   
           for i = 0 to len - 1 do
  -            let innerState', outerState' = folder.Invoke (Int32WithMeasure<'Tag> i, innerState, array.[i], outerState)
  +            let innerState', outerState' = folder.Invoke (Tag.ofInt i, innerState, array.[i], outerState)
               innerState <- innerState'
               outerState <- outerState'
   
  
positive.code:         let mutable state = state
  
          for i = len - 1 downto 0 do
              let result, state' = mapping.Invoke (Int32WithMeasure<'Tag> i, array.[i], state)
              results.[i] <- result
              state <- state'
  
  
negative.code:         let mutable state = state
  
          for i = 0 to len - 1 do
              let result, state' = mapping.Invoke (Tag.ofInt i, array.[i], state)
              results.[i] <- result
              state <- state'
  
  