X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fapps_2%2Fmodels%2Fveq.ma;h=4d3d16c1e2ca2be618b74b76c9cca1991c93d48a;hb=cc600ed1e115d5566947288d532a1e89d989227f;hp=a64dc2b1937c1360196bd3fe48a3e630c006c870;hpb=5a0d5df90ad4096c4d7bdc50ce69cf8673ea6e57;p=helm.git

diff --git a/matita/matita/contribs/lambdadelta/apps_2/models/veq.ma b/matita/matita/contribs/lambdadelta/apps_2/models/veq.ma
index a64dc2b19..4d3d16c1e 100644
--- a/matita/matita/contribs/lambdadelta/apps_2/models/veq.ma
+++ b/matita/matita/contribs/lambdadelta/apps_2/models/veq.ma
@@ -1,3 +1,4 @@
+
 (**************************************************************************)
 (*       ___                                                              *)
 (*      ||M||                                                             *)
@@ -14,7 +15,7 @@
 
 include "apps_2/models/model_props.ma".
 
-(* EVALUATION EQUIVALENCE  **************************************************)
+(* EVALUATION EQUIVALENCE ***************************************************)
 
 definition veq (M): relation (evaluation M) ≝
                     λv1,v2. ∀d. v1 d ≗ v2 d.
@@ -26,11 +27,70 @@ interpretation "evaluation equivalence (model)"
 
 lemma veq_refl (M): is_model M →
                     reflexive … (veq M).
-/2 width=1 by mq/ qed.
-(*
-lemma veq_sym: ∀M. symmetric … (veq M).
-// qed-.
-
-theorem veq_trans: ∀M. transitive … (veq M).
-// qed-.
-*)
\ No newline at end of file
+/2 width=1 by mr/ qed.
+
+lemma veq_repl (M): is_model M →
+                    replace_2 … (veq M) (veq M) (veq M).
+/2 width=5 by mq/ qed-.
+
+lemma veq_sym (M): is_model M → symmetric … (veq M).
+/3 width=5 by veq_repl, veq_refl/ qed-.
+
+lemma veq_trans (M): is_model M → Transitive … (veq M).
+/3 width=5 by veq_repl, veq_refl/ qed-.
+
+lemma veq_canc_sn (M): is_model M → left_cancellable … (veq M).
+/3 width=3 by veq_trans, veq_sym/ qed-.
+
+lemma veq_canc_dx (M): is_model M → right_cancellable … (veq M).
+/3 width=3 by veq_trans, veq_sym/ qed-.
+
+(* Properties with evaluation push ******************************************)
+
+theorem vpush_swap (M): is_model M →
+                        ∀i1,i2. i1 ≤ i2 →
+                        ∀lv,d1,d2. ⫯[i1←d1] ⫯[i2←d2] lv ≗{M} ⫯[↑i2←d2] ⫯[i1←d1] lv.
+#M #HM #i1 #i2 #Hi12 #lv #d1 #d2 #j
+elim (lt_or_eq_or_gt j i1) #Hji1 destruct
+[ lapply (lt_to_le_to_lt … Hji1 Hi12) #Hji2
+  >vpush_lt // >vpush_lt // >vpush_lt /2 width=1 by lt_S/ >vpush_lt //
+  /2 width=1 by veq_refl/
+| >vpush_eq >vpush_lt /2 width=1 by monotonic_le_plus_l/ >vpush_eq
+  /2 width=1 by mr/
+| >vpush_gt // elim (lt_or_eq_or_gt (↓j) i2) #Hji2 destruct
+  [ >vpush_lt // >vpush_lt /2 width=1 by lt_minus_to_plus/ >vpush_gt //
+    /2 width=1 by veq_refl/
+  | >vpush_eq <(lt_succ_pred … Hji1) >vpush_eq
+    /2 width=1 by mr/
+  | lapply (le_to_lt_to_lt … Hi12 Hji2) #Hi1j
+    >vpush_gt // >vpush_gt /2 width=1 by lt_minus_to_plus_r/ >vpush_gt //
+    /2 width=1 by veq_refl/
+  ]
+]
+qed.
+
+lemma vpush_comp (M): is_model M →
+                      ∀i. compatible_3 … (vpush M i) (sq M) (veq M) (veq M).
+#M #HM #i #d1 #d2 #Hd12 #lv1 #lv2 #HLv12 #j
+elim (lt_or_eq_or_gt j i) #Hij destruct
+[ >vpush_lt // >vpush_lt //
+| >vpush_eq >vpush_eq //
+| >vpush_gt // >vpush_gt //
+]
+qed-.
+
+(* Properies with term interpretation ***************************************) 
+
+lemma ti_comp (M): is_model M →
+                   ∀T,gv1,gv2. gv1 ≗ gv2 → ∀lv1,lv2. lv1 ≗ lv2 →
+                   ⟦T⟧[gv1, lv1] ≗{M} ⟦T⟧[gv2, lv2].
+#M #HM #T elim T -T * [||| #p * | * ]
+[ /4 width=5 by seq_trans, seq_sym, ms/
+| /4 width=5 by seq_sym, ml, mq/
+| /4 width=3 by seq_trans, seq_sym, mg/
+| /6 width=5 by vpush_comp, seq_sym, md, mc, mq/
+| /5 width=1 by vpush_comp, mi, mr/
+| /4 width=5 by seq_sym, ma, mp, mq/
+| /4 width=5 by seq_sym, me, mq/
+]
+qed.