From 24a0d9c9f72b54151f87332334f8ac488658351c Mon Sep 17 00:00:00 2001 From: Josh Chen Date: Wed, 19 Sep 2018 15:07:05 +0200 Subject: Renaming --- Proj.thy | 43 ------------------------------------------- 1 file changed, 43 deletions(-) delete mode 100644 Proj.thy (limited to 'Proj.thy') diff --git a/Proj.thy b/Proj.thy deleted file mode 100644 index e76e8d3..0000000 --- a/Proj.thy +++ /dev/null @@ -1,43 +0,0 @@ -(* -Title: Proj.thy -Author: Joshua Chen -Date: 2018 - -Projection functions \fst\ and \snd\ for the dependent sum type. -*) - -theory Proj -imports HoTT_Methods Prod Sum - -begin - - -definition fst :: "t \ t" where "fst p \ ind\<^sub>\ (\x y. x) p" -definition snd :: "t \ t" where "snd p \ ind\<^sub>\ (\x y. y) p" - -lemma fst_type: - assumes "A: U i" and "B: A \ U i" and "p: \x:A. B x" shows "fst p: A" -unfolding fst_def by (derive lems: assms) - -lemma fst_comp: - assumes "A: U i" and "B: A \ U i" and "a: A" and "b: B a" shows "fst \ a" -unfolding fst_def by compute (derive lems: assms) - -lemma snd_type: - assumes "A: U i" and "B: A \ U i" and "p: \x:A. B x" shows "snd p: B (fst p)" -unfolding snd_def proof (derive lems: assms) - show "\p. p: \x:A. B x \ fst p: A" using assms(1-2) by (rule fst_type) - - fix x y assume asm: "x: A" "y: B x" - show "y: B (fst )" by (derive lems: asm assms fst_comp) -qed - -lemma snd_comp: - assumes "A: U i" and "B: A \ U i" and "a: A" and "b: B a" shows "snd \ b" -unfolding snd_def by (derive lems: assms) - -lemmas Proj_types [intro] = fst_type snd_type -lemmas Proj_comps [comp] = fst_comp snd_comp - - -end -- cgit v1.2.3