+++ /dev/null
-(**************************************************************************)
-(* ___ *)
-(* ||M|| *)
-(* ||A|| A project by Andrea Asperti *)
-(* ||T|| *)
-(* ||I|| Developers: *)
-(* ||T|| The HELM team. *)
-(* ||A|| http://helm.cs.unibo.it *)
-(* \ / *)
-(* \ / This file is distributed under the terms of the *)
-(* v GNU General Public License Version 2 *)
-(* *)
-(**************************************************************************)
-
-include "static_2/notation/relations/topiso_2.ma".
-include "static_2/syntax/term.ma".
-
-(* HEAD EQUIVALENCE FOR TERMS ***********************************************)
-
-(* Basic_2A1: includes: tsts_atom tsts_pair *)
-inductive theq: relation term ≝
-| theq_sort: ∀s1,s2. theq (⋆s1) (⋆s2)
-| theq_lref: ∀i. theq (#i) (#i)
-| theq_gref: ∀l. theq (§l) (§l)
-| theq_pair: ∀I,V1,V2,T1,T2. theq (②{I}V1.T1) (②{I}V2.T2)
-.
-
-interpretation "head equivalence (term)" 'TopIso T1 T2 = (theq T1 T2).
-
-(* Basic inversion lemmas ***************************************************)
-
-fact theq_inv_sort1_aux: ∀X,Y. X ⩳ Y → ∀s1. X = ⋆s1 →
- ∃s2. Y = ⋆s2.
-#X #Y * -X -Y
-[ #s1 #s2 #s #H destruct /2 width=2 by ex_intro/
-| #i #s #H destruct
-| #l #s #H destruct
-| #I #V1 #V2 #T1 #T2 #s #H destruct
-]
-qed-.
-
-(* Basic_1: was just: iso_gen_sort *)
-lemma theq_inv_sort1: ∀Y,s1. ⋆s1 ⩳ Y →
- ∃s2. Y = ⋆s2.
-/2 width=4 by theq_inv_sort1_aux/ qed-.
-
-fact theq_inv_lref1_aux: ∀X,Y. X ⩳ Y → ∀i. X = #i → Y = #i.
-#X #Y * -X -Y //
-[ #s1 #s2 #j #H destruct
-| #I #V1 #V2 #T1 #T2 #j #H destruct
-]
-qed-.
-
-(* Basic_1: was: iso_gen_lref *)
-lemma theq_inv_lref1: ∀Y,i. #i ⩳ Y → Y = #i.
-/2 width=5 by theq_inv_lref1_aux/ qed-.
-
-fact theq_inv_gref1_aux: ∀X,Y. X ⩳ Y → ∀l. X = §l → Y = §l.
-#X #Y * -X -Y //
-[ #s1 #s2 #k #H destruct
-| #I #V1 #V2 #T1 #T2 #k #H destruct
-]
-qed-.
-
-lemma theq_inv_gref1: ∀Y,l. §l ⩳ Y → Y = §l.
-/2 width=5 by theq_inv_gref1_aux/ qed-.
-
-fact theq_inv_pair1_aux: ∀T1,T2. T1 ⩳ T2 →
- ∀J,W1,U1. T1 = ②{J}W1.U1 →
- ∃∃W2,U2. T2 = ②{J}W2.U2.
-#T1 #T2 * -T1 -T2
-[ #s1 #s2 #J #W1 #U1 #H destruct
-| #i #J #W1 #U1 #H destruct
-| #l #J #W1 #U1 #H destruct
-| #I #V1 #V2 #T1 #T2 #J #W1 #U1 #H destruct /2 width=3 by ex1_2_intro/
-]
-qed-.
-
-(* Basic_1: was: iso_gen_head *)
-(* Basic_2A1: was: tsts_inv_pair1 *)
-lemma theq_inv_pair1: ∀J,W1,U1,T2. ②{J}W1.U1 ⩳ T2 →
- ∃∃W2,U2. T2 = ②{J}W2. U2.
-/2 width=7 by theq_inv_pair1_aux/ qed-.
-
-fact theq_inv_pair2_aux: ∀T1,T2. T1 ⩳ T2 →
- ∀J,W2,U2. T2 = ②{J}W2.U2 →
- ∃∃W1,U1. T1 = ②{J}W1.U1.
-#T1 #T2 * -T1 -T2
-[ #s1 #s2 #J #W2 #U2 #H destruct
-| #i #J #W2 #U2 #H destruct
-| #l #J #W2 #U2 #H destruct
-| #I #V1 #V2 #T1 #T2 #J #W2 #U2 #H destruct /2 width=3 by ex1_2_intro/
-]
-qed-.
-
-(* Basic_2A1: was: tsts_inv_pair2 *)
-lemma theq_inv_pair2: ∀J,T1,W2,U2. T1 ⩳ ②{J}W2.U2 →
- ∃∃W1,U1. T1 = ②{J}W1.U1.
-/2 width=7 by theq_inv_pair2_aux/ qed-.
-
-(* Advanced inversion lemmas ************************************************)
-
-lemma theq_inv_pair: ∀I1,I2,V1,V2,T1,T2. ②{I1}V1.T1 ⩳ ②{I2}V2.T2 →
- I1 = I2.
-#I1 #I2 #V1 #V2 #T1 #T2 #H elim (theq_inv_pair1 … H) -H
-#V0 #T0 #H destruct //
-qed-.
-
-(* Basic properties *********************************************************)
-
-(* Basic_1: was: iso_refl *)
-(* Basic_2A1: was: tsts_refl *)
-lemma theq_refl: reflexive … theq.
-* //
-* /2 width=1 by theq_lref, theq_gref/
-qed.
-
-(* Basic_2A1: was: tsts_sym *)
-lemma theq_sym: symmetric … theq.
-#T1 #T2 * -T1 -T2 /2 width=3 by theq_sort/
-qed-.
-
-(* Basic_2A1: was: tsts_dec *)
-lemma theq_dec: ∀T1,T2. Decidable (T1 ⩳ T2).
-* [ * #s1 | #I1 #V1 #T1 ] * [1,3,5,7: * #s2 |*: #I2 #V2 #T2 ]
-[ /3 width=1 by theq_sort, or_introl/
-|2,3,13:
- @or_intror #H
- elim (theq_inv_sort1 … H) -H #x #H destruct
-|4,6,14:
- @or_intror #H
- lapply (theq_inv_lref1 … H) -H #H destruct
-|5:
- elim (eq_nat_dec s1 s2) #Hs12 destruct /2 width=1 by or_introl/
- @or_intror #H
- lapply (theq_inv_lref1 … H) -H #H destruct /2 width=1 by/
-|7,8,15:
- @or_intror #H
- lapply (theq_inv_gref1 … H) -H #H destruct
-|9:
- elim (eq_nat_dec s1 s2) #Hs12 destruct /2 width=1 by or_introl/
- @or_intror #H
- lapply (theq_inv_gref1 … H) -H #H destruct /2 width=1 by/
-|10,11,12:
- @or_intror #H
- elim (theq_inv_pair1 … H) -H #X1 #X2 #H destruct
-|16:
- elim (eq_item2_dec I1 I2) #HI12 destruct
- [ /3 width=1 by theq_pair, or_introl/ ]
- @or_intror #H
- lapply (theq_inv_pair … H) -H /2 width=1 by/
-]
-qed-.
-
-(* Basic_2A1: removed theorems 2:
- tsts_inv_atom1 tsts_inv_atom2
-*)