XPath - syntaktická pravidla

[20] PathExpr   ::=  AbsolutePathExpr |  RelativePathExpr
[22] AbsolutePathExpr   ::=  ("/"  RelativePathExpr?)  |  ("//"  RelativePathExpr)
[23] RelativePathExpr   ::=  StepExpr (("/"  |  "//")  StepExpr)*
[24] StepExpr   ::=  AxisStep |  GeneralStep
[25] AxisStep   ::=  (Axis?  NodeTest StepQualifiers)  |  AbbreviatedStep