arglist definition

[ | expr | param:=expr ][, ...]

A list of zero or more exprs that are assigned to the parameters of the procedure.

• A positional parameter may be skipped by omitting the expression. Only optional parameters may be skipped.
• Positional parameter assignment is done with expr. Each parameter is assigned in turn. By name parameter assignment may follow.
• By name parameter assignment is done with param:=expr. All following parameters must be assigned by name.