Package list-nth-def: Definition of the list nth function
Information
name | list-nth-def |
version | 1.39 |
description | Definition of the list nth function |
author | Joe Hurd <joe@gilith.com> |
license | HOLLight |
provenance | HOL Light theory extracted on 2012-06-16 |
requires | bool list-dest natural |
show | Data.Bool Data.List Number.Natural |
Files
- Package tarball list-nth-def-1.39.tgz
- Theory file list-nth-def.thy (included in the package tarball)
Defined Constant
- Data
- List
- nth
- List
Theorems
⊦ ∀h t. nth (h :: t) 0 = h
⊦ ∀h t n. n < length t ⇒ nth (h :: t) (suc n) = nth t n
Input Type Operators
- →
- bool
- Data
- List
- list
- List
- Number
- Natural
- natural
- Natural
Input Constants
- =
- select
- Data
- Bool
- ∀
- ∧
- ⇒
- ∃
- ∃!
- ⊤
- List
- ::
- head
- length
- tail
- Bool
- Number
- Natural
- <
- suc
- zero
- Natural
Assumptions
⊦ ⊤
⊦ (∃) = λp. p ((select) p)
⊦ ∀t. (∀x. t) ⇔ t
⊦ (∀) = λp. p = λx. ⊤
⊦ ∀t. t ⇒ ⊤ ⇔ ⊤
⊦ (⇒) = λp q. p ∧ q ⇔ p
⊦ ∀h t. head (h :: t) = h
⊦ ∀h t. tail (h :: t) = t
⊦ (∧) = λp q. (λf. f p q) = λf. f ⊤ ⊤
⊦ (∃) = λp. ∀q. (∀x. p x ⇒ q) ⇒ q
⊦ ∀p. (∀x. ∃y. p x y) ⇔ ∃y. ∀x. p x (y x)
⊦ (∃!) = λp. (∃) p ∧ ∀x y. p x ∧ p y ⇒ x = y
⊦ ∀e f. ∃!fn. fn 0 = e ∧ ∀n. fn (suc n) = f (fn n) n