In order to make the definitions more readable, but still have a rigid definition of the terms, some extra comments have been added to some of the definitions. These comments are enclosed in square brackets. Argument is an expression supplied to a function or subroutine , and it provides data on which the call can work on. Assignment is a clause in which second token is the equal sign. Blanks are characters which glyphs are empty space, either vertically or horizontally.
Character string is an finite, ordered, and possibly empty set of characters .
Clause is a non-empty collection of tokens in a REXX script. The tokens making up a clause are all the consecutive tokens delimited by two consecutive clause delimiters . Clause delimiter is a non-empty sequence of elements of a subset of tokens , normally the linefeed and the semicolon. Also the start and end of a REXX script are considered clause delimiters. Also colon is a clause separator, but it is only valid after a label.