Specifying Data Nodes in Conditions 

Data nodes as dnodeoperands of Preconditions, Assertions, or Conditions can be specified as follows:

●     If the name node – specified according to the addressing rules – has a letter or underscore as its first character and only letters, numbers, hyphens, or underscores at all other positions, it can be specified directly.

●     The special names $ref and $alias can also be specified directly.

●     All other names must be specified in the form ref('node'). This particularly applies to the specification of a data root using .root.

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