claziep () = a - y + l

pa pr () = y p a r a

ap pc () = a r a p y

_+ _- () = a y

c - p + a - p () = 1 = p = - c = + a = p + 1 - c + a - c + a - p + a - p

1 _- () = a

_+ 1 () = p

p p p p rca () = - - - - gyram

minus bar = () bar gyram ap pr pa pc

1 bar () = + pr gyram bar