renaming

[helm.git] / matita / matita / contribs / lambdadelta / basic_2 / static / ffdeq_ffdeq.ma

diff --git a/matita/matita/contribs/lambdadelta/basic_2/static/ffdeq_ffdeq.ma b/matita/matita/contribs/lambdadelta/basic_2/static/ffdeq_ffdeq.ma
index 40a805259638e00110e6e0823d9b1333309e904e..cbd1284cea26f1dd7566471736bb0cd922e28e34 100644 (file)
--- a/matita/matita/contribs/lambdadelta/basic_2/static/ffdeq_ffdeq.ma
+++ b/matita/matita/contribs/lambdadelta/basic_2/static/ffdeq_ffdeq.ma
@@ -39,3 +39,14 @@ theorem ffdeq_canc_sn: ∀h,o,G,G1,G2,L,L1,L2,T,T1,T2.
 theorem ffdeq_canc_dx: ∀h,o,G1,G2,G,L1,L2,L,T1,T2,T.
                        ⦃G1, L1, T1⦄ ≛[h, o] ⦃G, L, T⦄ → ⦃G2, L2, T2⦄ ≛[h, o] ⦃G, L, T⦄ → ⦃G1, L1, T1⦄ ≛[h, o] ⦃G2, L2, T2⦄.
 /3 width=5 by ffdeq_trans, ffdeq_sym/ qed-.
+
+(* Main inversion lemmas with degree-based equivalence on terms *************)
+
+theorem ffdeq_tdneq_repl_dx: ∀h,o,G1,G2,L1,L2,T1,T2. ⦃G1, L1, T1⦄ ≛[h, o] ⦃G2, L2, T2⦄ →
+                             ∀U1,U2. ⦃G1, L1, U1⦄ ≛[h, o] ⦃G2, L2, U2⦄ →
+                             (T2 ≛[h, o] U2 → ⊥) → (T1 ≛[h, o] U1 → ⊥).
+#h #o #G1 #G2 #L1 #L2 #T1 #T2 #HT #U1 #U2 #HU #HnTU2 #HTU1
+elim (ffdeq_inv_gen_sn … HT) -HT #_ #_ #HT
+elim (ffdeq_inv_gen_sn … HU) -HU #_ #_ #HU
+/3 width=5 by tdeq_repl/
+qed-.