Definitions | {x:A| B(x)} , x.A(x),  b, i <z j, inr x , case b of inl(x) => s(x) | inr(y) => t(y), x:A B(x), b, f(a), A B, , Ax, inl x , left + right, x:A B(x), s = t, Type, #$n, i z j, -n, a < b, P Q, i > j, , , , Unit, , True, T, ff, P  Q, P & Q, tt, P  Q, x:A. B(x), t T, if b then t else f fi , |i|, P   Q |