Definitions | es-decl(es;ds;da), ES, Interface(ds;da;A), Knd, Id, Type, <a, b>, f(a), interface-right(X), s = t, x:A B(x), E, AbsInterface(A), es-interface-right(X), t T, [[X]], left + right, Top, x:A. B(x), P  Q, s ~ t, in-interface(es;X;e), f o g , can-apply(f;x), do-apply(f;x), fpf dom compose compseq tag def, P   Q, P & Q, , if b then t else f fi , fpf ap compose compseq tag def, interface-val(es;X;e), invert-union(x), ff, A, False, t.1, b, x:A B(x), a:A fp B(a), inr x , , Unit, x:A.B(x), Void |