anchor.diff:      Set<LrItem<'Nonterminal, 'Terminal, 'Lookahead>>
   
   //
  -type internal ShiftOrReduce =
  -    /// Shift into a state.
  -    | Shift of ParserStateId
  +type internal ParserStatePositionGraphAction<'Terminal when 'Terminal : comparison> =
  +    /// Shift the specified terminal (token) onto the parser stack.
  +    | Shift of 'Terminal
       /// Reduce by a production rule.
       | Reduce of ReductionRuleId
  +    /// Accept.
  +    | Accept
   
   /// A node in a Parser State Position Graph (PSPG).
   type internal ParserStatePositionGraphNode<'Nonterminal, 'Terminal, 'Lookahead
  
positive.code:             match Map.tryFind tableKey tableGenState.Table with
              | None ->
                  // Create a new 'accept' action for this table entry.
                  Set.singleton Accept
              | Some entry ->
                  // Create a new 'accept' action and add it to the existing table entry.
                  Set.add Accept entry
  
          // Update the table with the new entry.
          (),
  
negative.code:                 else
                      closure items'
  
              // Compute the closure, starting with the specified initial items.
              closure items
  
          /// Moves the 'dot' (the current parser position) past the
  