Syntax diagrams

All elements of the pascal language are explained in syntax diagrams. Syntax diagrams are like ow charts. Reading a syntax diagram means getting from the left side to the right side, following the arrows. When the right side of a syntax diagram is reached, and it ends with a single arrow, this means the syntax diagram is continued on the next line. If the line ends on 2 arrows pointing to each other, then the diagram is ended.

Syntactical elements are written like this
-- --                         -----------------------------------------------
    syntactical elements are like this
Keywords which must be typed exactly as in the diagram:
-- --keywords are like this---------------------------------------------------- -
When something can be repeated, there is an arrow around it:
-- ---|this can be repeated----------------------------------------------------
     6-----------------
When there are dierent possibilities, they are listed in rows:
-- ---|-First possibility----------------------------------------------------------
     -Second possibility--
Note, that one of the possibilities can be empty:
-- --------------------------------------------------------------------------
     --First possibility---|
     -Second possibility--|
This means that both the rst or second possibility are optional. Of course, all these elements can be combined and nested.