[1]    LocationPath            ::=    RelativeLocationPath               
                                        | AbsoluteLocationPath             
  [2]    AbsoluteLocationPath    ::=    '/' RelativeLocationPath?          
                                        | AbbreviatedAbsoluteLocationPath  
  [3]    RelativeLocationPath    ::=    Step                               
                                        | RelativeLocationPath '/' Step
                                        | AbbreviatedRelativeLocationPath  

 [4]    Step             ::=    AxisSpecifier NodeTest Predicate*
                                | AbbreviatedStep                         
 [5]    AxisSpecifier    ::=    AxisName '::'                             
                                | AbbreviatedAxisSpecifier                

   [6]    AxisName    ::=    'ancestor'            
                             | 'ancestor-or-self'  
                             | 'attribute'         
                             | 'child'             
                             | 'descendant'        
                             | 'descendant-or-self'
                             | 'following'         
                             | 'following-sibling' 
                             | 'namespace'         
                             | 'parent'            
                             | 'preceding'         
                             | 'preceding-sibling' 
                             | 'self'              

   [7]    NodeTest    ::=    NameTest                                  
                             | NodeType '(' ')'                        
                             | 'processing-instruction' '(' Literal ')'

   [8]    Predicate        ::=    '[' PredicateExpr ']'
   [9]    PredicateExpr    ::=    Expr                 


   [10]    AbbreviatedAbsoluteLocationPath    ::=    '//'
						     RelativeLocationPath
   [11]    AbbreviatedRelativeLocationPath    ::=
						     RelativeLocationPath '//' Step
   [12]    AbbreviatedStep    ::=    '.'
                                     | '..'
   [13]    AbbreviatedAxisSpecifier    ::=    '@'?

   [14]    Expr           ::=    OrExpr           
   [15]    PrimaryExpr    ::=    VariableReference
                                 | '(' Expr ')'   
                                 | Literal        
                                 | Number         
                                 | FunctionCall   


   [16]    FunctionCall    ::=    [152]FunctionName '(' ( [153]Argument (
   ',' [154]Argument )* )? ')'
   [17]    Argument    ::=    [155]Expr


  [18]    UnionExpr     ::=    [159]PathExpr                                   
                               | [160]UnionExpr '|' [161]PathExpr              
  [19]    PathExpr      ::=    [162]LocationPath                               
                               | [163]FilterExpr                               
                               | [164]FilterExpr '/' [165]RelativeLocationPath 
                               | [166]FilterExpr '//' [167]RelativeLocationPath
  [20]    FilterExpr    ::=    [168]PrimaryExpr                                
                               | [169]FilterExpr [170]Predicate                


  [21]    OrExpr            ::=    [186]AndExpr                                
                                   | [187]OrExpr 'or' [188]AndExpr             
  [22]    AndExpr           ::=    [189]EqualityExpr                           
                                   | [190]AndExpr 'and' [191]EqualityExpr      
  [23]    EqualityExpr      ::=    [192]RelationalExpr                         
                                   | [193]EqualityExpr '=' [194]RelationalExpr 
                                   | [195]EqualityExpr '!=' [196]RelationalExpr
  [24]    RelationalExpr    ::=    [197]AdditiveExpr                           
                                   | [198]RelationalExpr '<' [199]AdditiveExpr 
                                   | [200]RelationalExpr '>' [201]AdditiveExpr 
                                   | [202]RelationalExpr '<=' [203]AdditiveExpr
                                   | [204]RelationalExpr '>=' [205]AdditiveExpr
   [25]    AdditiveExpr    ::=    [212]MultiplicativeExpr
   | [213]AdditiveExpr '+' [214]MultiplicativeExpr
   | [215]AdditiveExpr '-' [216]MultiplicativeExpr
   [26]    MultiplicativeExpr    ::=    [217]UnaryExpr
   | [218]MultiplicativeExpr [219]MultiplyOperator [220]UnaryExpr
   | [221]MultiplicativeExpr 'div' [222]UnaryExpr
   | [223]MultiplicativeExpr 'mod' [224]UnaryExpr
   [27]    UnaryExpr    ::=    [225]UnionExpr
   | '-' [226]UnaryExpr

   [28]    ExprToken    ::=    '(' | ')' | '[' | ']' | '.' | '..' | '@' |
   ',' | '::'
   | [249]NameTest
   | [250]NodeType
   | [251]Operator
   | [252]FunctionName
   | [253]AxisName
   | [254]Literal
   | [255]Number
   | [256]VariableReference
   [29]    Literal    ::=    '"' [^"]* '"'
   | "'" [^']* "'"
   [30]    Number    ::=    [257]Digits ('.' [258]Digits?)?
   | '.' [259]Digits
   [31]    Digits    ::=    [0-9]+
   [32]    Operator    ::=    [260]OperatorName
   | [261]MultiplyOperator
   | '/' | '//' | '|' | '+' | '-' | '=' | '!=' | '<' | '<=' | '>' | '>='
   [33]    OperatorName    ::=    'and' | 'or' | 'mod' | 'div'
   [34]    MultiplyOperator    ::=    '*'
   [35]    FunctionName    ::=    [262]QName - [263]NodeType
   [36]    VariableReference    ::=    '$' [264]QName
   [37]    NameTest    ::=    '*'
   | [265]NCName ':' '*'
   | [266]QName
   [38]    NodeType    ::=    'comment'
   | 'text'
   | 'processing-instruction'
   | 'node'
   [39]    ExprWhitespace    ::=    [267]S