Def C+[a;q] == map(c. < 1of(c),a.2of(c) > ;C) @ [ < q,nil > ]

Thm* Alph,St:Type, C:NComp(Alph;St), a:Alph, q:St. C+[a;q] NComp(Alph;St)

Thm* A:Type, B:(AType), p:a:AB(a). 2of(p) B(1of(p))

Thm* A:Type, B:(AType), p:a:AB(a). 1of(p) A

Def map(f;as) == Case of as; nil nil ; a.as' f(a).map(f;as') (recursive)

Thm* A,B:Type, f:(AB), l:A*. map(f;l) B*

Def as @ bs == Case of as; nil bs ; a.as' a.(as' @ bs) (recursive)

Thm* T:Type, as,bs:T*. (as @ bs) T*