証明のテキスト化の準備

導出:

  1. false-elim = initial : ⊥ → P
  2. true-intro = final : P → T
  3. forall-elim = instantiate = projection : ∀x∈X.P(x) → P(a)
  4. exists-intro = uninstantiate = injection : P(a) → ∃x∈X.P(x)

リーズニング:

  1. Forall-Intro-Right :: (x∈X. φ(x):A→P(x)) ⇒ (A → ∀x∈X.P(x))
  2. Exists-Intro-Left :: (x∈X. φ(x):P(x)→B) ⇒ (∃x∈X.P(x) → B)
  3. Imp-Intro :: (A, B → C) ⇒ (A → C<*B)
  4. Imp-Elim :: (A → C<*B) ⇒ (A, B → C)
  5. Comp :: (Γ → Δ), (Δ → Σ) ⇒ (Γ → Σ)
  6. Not-Intro :: (Γ, A → ⊥) ⇒ (Γ → ¬A)
  7. Not-Elim :: (Γ → ¬A) ⇒ (Γ , A → ⊥)

ブロック(ボックス):

キーワード 短縮 意味
sequence seq Compの連続
conjunction conj Forall-Intro-Right
disjunction disj Exists-Intro-Left
implication imp Imp-Intro
application app Imp-Elim
absurd abs Not-Intro
contradict contr Not-Elim

テキスト化の例(まだ未定):

begin implication
  postulate A
  assume B
  ...
  C
end implicatin
Now we have
  A → (C < B)
begin sequence
  postilate ∀x∈X.P(x)
  by instantiate[X, P, a]
  P(a)  --(1)
  by premise P12
  P(a) > B --(2)
  from 1, 2 by MP
  B
end sequence
Now we have ∀x∈X.P(x) → B