--- /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/syntax/genv.ma".
+include "static_2/relocation/drops_vector.ma".
+
+(* GENERIC COMPUTATION PROPERTIES *******************************************)
+
+definition nf ≝ λRR:relation4 genv lenv term term. λRS:relation term.
+ λG,L,T. NF … (RR G L) RS T.
+
+definition candidate: Type[0] ≝ relation3 genv lenv term.
+
+definition CP0 ≝ λRR:relation4 genv lenv term term. λRS:relation term.
+ ∀G. d_liftable1 (nf RR RS G).
+
+definition CP1 ≝ λRR:relation4 genv lenv term term. λRS:relation term.
+ ∀G,L. ∃s. NF … (RR G L) RS (⋆s).
+
+definition CP2 ≝ λRP:candidate. ∀G. d_liftable1 (RP G).
+
+definition CP3 ≝ λRP:candidate.
+ ∀G,L,T,s. RP G L (ⓐ⋆s.T) → RP G L T.
+
+(* requirements for generic computation properties *)
+(* Basic_1: includes: nf2_lift1 *)
+(* Basic_2A1: includes: gcp0_lifts *)
+(* Basic_2A1: includes: gcp2_lifts *)
+record gcp (RR:relation4 genv lenv term term) (RS:relation term) (RP:candidate) : Prop ≝
+{ cp0: CP0 RR RS;
+ cp1: CP1 RR RS;
+ cp2: CP2 RP;
+ cp3: CP3 RP
+}.
+
+(* Basic properties *********************************************************)
+
+(* Basic_1: was only: sns3_lifts1 *)
+(* Basic_2A1: was: gcp2_lifts_all *)
+lemma gcp2_all: ∀RR,RS,RP. gcp RR RS RP → ∀G. d_liftable1_all (RP G).
+/3 width=7 by cp2, d1_liftable_liftable_all/ qed.