quox/examples/eta.quox

26 lines
820 B
Plaintext
Raw Permalink Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

load "misc.quox"
namespace eta {
def0 Π : (A : ★) → (A → ★) → ★ = λ A B ⇒ (x : A) → B x
def0 Σ : (A : ★) → (A → ★) → ★ = λ A B ⇒ (x : A) × B x
def0 function : (A : ★) → (B : A → Type) → (P : Π A B → ★) → (f : Π A B) →
P (λ x ⇒ f x) → P f =
λ A B P f p ⇒ p
def0 box : (A : ★) → (P : [ω.A] → ★) → (e : [ω.A]) →
P [case1 e return A of {[x] ⇒ x}] → P e =
λ A P e p ⇒ p
def0 pair : (A : ★) → (B : A → ★) → (P : Σ A B → ★) → (e : Σ A B) →
P (fst e, snd e) → P e =
λ A B P e p ⇒ p
-- not exactly η, but kinda related
def0 from-false : (A : ★) → (P : (0.False → A) → ★) → (f : 0.False → A) →
P (void A) → P f =
λ A P f p ⇒ p
}