
S ⊆ N
S
R ⊆ N
2
∀x (x ∈ S ⇔ ∃t R(x, t));
R ⊆ N
k+1
∀x (x ∈ S ⇔ ∃t
1
. . . ∃t
k
R(x, t
1
, . . . , t
k
));
S = dom (f)
S = range (f)
⇒ S = ∅
∀x (x ∈ S ⇔ ∃t(x + t + 1 = 0)) S 6= ∅
f : N → N S = range (f)
x ∈ S ⇔ ∃t (x = f (t))
⇒
⇒ R(x, t
1
, . . . , t
k
)
f(x) = µt R(x, (t)
1
, . . . , (t)
k
) f
f(x) ↓⇔ ∃t
1
. . . ∃t
k
R(x, t) S = dom (f)
⇒ S = dom (g) g
f(x) = x ·(0(g(x)) + 1) f
range (f) = S
⇒ S = ∅
S 6= ∅ e
e ∈ N
T (e, x, t) f(x) ' U(µt (T (e, x, t)))
t
e x x
T (e, x, t) t
a
0
∈ S
g(t) =
½
U((t)
1
), T (e, (t)
0
, (t)
1
)
a
0
,
g ¤