name | list-nub |
version | 1.13 |
description | Definitions and theorems about the list nub function |
author | Joe Hurd <joe@gilith.com> |
license | MIT |
show | Data.Bool Data.List |
⊦ ∀l. nub (nub l) = nub l
⊦ ∀l. nubReverse (nubReverse l) = nubReverse l
⊦ ∀l. toSet (nub l) = toSet l
⊦ ∀l. toSet (nubReverse l) = toSet l
⊦ ∀l. Number.Natural.≤ (length (nub l)) (length l)
⊦ ∀l. Number.Natural.≤ (length (nubReverse l)) (length l)
⊦ ∀l. nub l = reverse (nubReverse (reverse l))
⊦ ∀l x. member x (nub l) ⇔ member x l
⊦ ∀l x. member x (nubReverse l) ⇔ member x l
⊦ nubReverse [] = [] ∧
∀h t.
nubReverse (h :: t) =
if member h t then nubReverse t else h :: nubReverse t
⊦ T
⊦ ∀n. Number.Natural.≤ n n
⊦ F ⇔ ∀p. p
⊦ ∀t. t ∨ ¬t
⊦ (~) = λp. p ⇒ F
⊦ (∃) = λP. P ((select) P)
⊦ ∀t. (∀x. t) ⇔ t
⊦ (∀) = λp. p = λx. T
⊦ ∀x. x = x ⇔ T
⊦ ∀l. reverse (reverse l) = l
⊦ ∀l. length (reverse l) = length l
⊦ (⇒) = λp q. p ∧ q ⇔ p
⊦ ∀t. (t ⇔ T) ∨ (t ⇔ F)
⊦ (¬T ⇔ F) ∧ (¬F ⇔ T)
⊦ ∀x l. member x l ⇔ Set.∈ x (toSet l)
⊦ ∀l x. member x (reverse l) ⇔ member x l
⊦ (∧) = λp q. (λf. f p q) = λf. f T T
⊦ ∀m n.
Number.Natural.≤ (Number.Natural.suc m) (Number.Natural.suc n) ⇔
Number.Natural.≤ m n
⊦ (∨) = λp q. ∀r. (p ⇒ r) ⇒ (q ⇒ r) ⇒ r
⊦ ∀s t. s = t ⇔ ∀x. Set.∈ x s ⇔ Set.∈ x t
⊦ ∀t1 t2. (if T then t1 else t2) = t1 ∧ (if F then t1 else t2) = t2
⊦ length [] = 0 ∧ ∀h t. length (h :: t) = Number.Natural.suc (length t)
⊦ ∀P. P [] ∧ (∀a0 a1. P a1 ⇒ P (a0 :: a1)) ⇒ ∀x. P x
⊦ ∀NIL' CONS'.
∃fn. fn [] = NIL' ∧ ∀a0 a1. fn (a0 :: a1) = CONS' a0 a1 (fn a1)
⊦ (∀x. member x [] ⇔ F) ∧ ∀x h t. member x (h :: t) ⇔ x = h ∨ member x t
⊦ (∀m. Number.Natural.≤ m 0 ⇔ m = 0) ∧
∀m n.
Number.Natural.≤ m (Number.Natural.suc n) ⇔
m = Number.Natural.suc n ∨ Number.Natural.≤ m n
⊦ ∀t. ((T ⇔ t) ⇔ t) ∧ ((t ⇔ T) ⇔ t) ∧ ((F ⇔ t) ⇔ ¬t) ∧ ((t ⇔ F) ⇔ ¬t)
⊦ ∀t. (T ∨ t ⇔ T) ∧ (t ∨ T ⇔ T) ∧ (F ∨ t ⇔ t) ∧ (t ∨ F ⇔ t) ∧ (t ∨ t ⇔ t)