# tokens
OR := "||"
AND := "&&"
POPEN := "("
PCLOSE := ")"

EQUAL := "="
LESS := "<"
LESS_OR_EQUAL := "<="
GREATER := ">"
GREATER_OR_EQUAL := ">="

INEQUALITY_SIGN = EQUAL
	| LESS
	| LESS_OR_EQUAL
	| GREATER
	| GREATER_OR_EQUAL

TRACK_FUNCTION := "anyTrackOf"
	| "allTrackOf"
	| "countTrackOf"
ALBUM_FUNCTION := "anyAlbumOf"
	| "allAlbumOf"
	| "countAlbumOf"
NUMBER := [0-9]+
ALBUM_ID := "mb" [0-9a-f]{16}
TRACK_ID := "mt" [0-9a-f]{16}
ARTIST_ID := "mi" [0-9a-f]{16}

# syntax
statement :=
	  TRACK_FUNCTION POPEN (ALBUM_ID | ARTIST_ID) PCLOSE INEQUALITY_SIGN NUMBER
	| ALBUM_FUNCTION POPEN (ARTIST_ID) PCLOSE INEQUALITY_SIGN NUMBER
	| ALBUM_ID
	| TRACK_ID
	| POPEN statement PCLOSE
	| statement ((AND | OR) statement)*