::= {import } program [ #machine := ] ( #auto | ) { ( | | auto := | | protect | private ) } end [ := ] . ::= ( "_" | ) { ( "_" | | ) } ::= "[" { } "]" ::= { } ::= [ "-" ] ::= . ::= "\"" { } "\"" ::= "*" { ( "_" | | ) } ::= | | | | / | fail | | ::= { } [ : ] "]" ::= "[" ::= "[[" ::= #machine := ::= preprocessor := ( | "[" "]" )