patterns                 pattern/action
{action}                 TRUE Pattern
exp{action}              Typical Pattern
re{action}               Regular Expression Pattern
cp{action}               Compound Pattern
p1,p2{action}            Range Pattern
BEGIN                    BEGIN pattern
INITIAL ( INITIALIZE )   INITIAL pattern
GROUP                    GROUP pattern
NOMATCH                  NOMATCH pattern
FINAL ( FINALIZE )       FINAL pattern
END                      END pattern
function                 function pattern