+++ /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 "lambda/rc_sat.ma".
-
-(* HIGHER ORDER REDUCIBILITY CANDIDATES ***************************************)
-
-(* An arity is a type of λ→ to be used as carrier for a h.o. r.c. *)
-
-(* The type of the higher order r.c.'s having a given carrier.
- * a h.o. r.c is implemented as an inductively defined metalinguistic function
- * [ a CIC function in the present case ].
- *)
-let rec HRC P ≝ match P with
- [ SORT ⇒ RC
- | ABST Q P ⇒ HRC Q → HRC P
- ].
-
-(* The default h.o r.c.
- * This is needed to complete the partial interpretation of types.
- *)
-let rec defHRC P ≝ match P return λP. HRC P with
- [ SORT ⇒ snRC
- | ABST Q P ⇒ λ_. defHRC P
- ].
-
-(* extensional equality *******************************************************)
-
-(* This is the extensional equalty of functions
- * modulo the extensional equality on the domain.
- * The functions may not respect extensional equality so reflexivity fails.
- *)
-let rec hrceq P ≝ match P return λP. HRC P → HRC P → Prop with
- [ SORT ⇒ λC1,C2. C1 ≅ C2
- | ABST Q P ⇒ λC1,C2. ∀B1,B2. hrceq Q B1 B2 → hrceq P (C1 B1) (C2 B2)
- ].
-
-interpretation
- "extensional equality (h.o. reducibility candidate)"
- 'Eq1 P C1 C2 = (hrceq P C1 C2).
-
-lemma symmetric_hrceq: ∀P. symmetric ? (hrceq P).
-#P (elim P) -P /4/
-qed.
-
-lemma transitive_hrceq: ∀P. transitive ? (hrceq P).
-#P (elim P) -P /5/
-qed.
-
-lemma reflexive_defHRC: ∀P. defHRC P ≅^P defHRC P.
-#P (elim P) -P (normalize) /2/
-qed.