| Ausdruck | -> Term | Vereinigung | Durchschnitt | Differenz |
| Vereinigung | -> "|" Term | Term "|" Term | Vereinigung "|" Term |
| Durchschnitt | -> Term "&" Term | Durchschnitt "&" Term |
| Differenz | -> Term "\" Term | Differenz "\" Term |
| Term | -> Element | Term Element |
| Element | -> Atom | Element "*" | Element "¯" | Element "~" |
| Atom | -> "Ø" | Zeichen | "(" Ausdruck ")" |
| Zeichen | -> "a" | "b" | ... |