The with statement specifies a record variable and a statement sequence. In these statements the qualification of field identifiers may be omitted, if they are to refer to the variable specified in the with clause. If the designator denotes a component of a structured variable, the selector is evaluated once (before the statement sequence). The with statement opens a new scope.
WithStatement = WITH designator DO StatementSequence END.
WITH t^ DO key:= 0; left:= NIL; right:= NIL END