(* Basic_2A1: includes: lsubr_fwd_drop2_pair *)
lemma lsubr_fwd_drops2_pair: ∀L1,L2. L1 ⫃ L2 →
- ∀I,K2,W,c,f. 𝐔⦃f⦄ → ⬇*[c, f] L2 ≡ K2.ⓑ{I}W →
- (∃∃K1. K1 ⫃ K2 & ⬇*[c, f] L1 ≡ K1.ⓑ{I}W) ∨
- ∃∃K1,V. K1 ⫃ K2 & ⬇*[c, f] L1 ≡ K1.ⓓⓝW.V & I = Abst.
+ ∀b,f,I,K2,W. 𝐔⦃f⦄ → ⬇*[b, f] L2 ≡ K2.ⓑ{I}W →
+ (∃∃K1. K1 ⫃ K2 & ⬇*[b, f] L1 ≡ K1.ⓑ{I}W) ∨
+ ∃∃K1,V. K1 ⫃ K2 & ⬇*[b, f] L1 ≡ K1.ⓓⓝW.V & I = Abst.
#L1 #L2 #H elim H -L1 -L2
-[ #L #I #K2 #W #c #f #_ #H
+[ #L #b #f #I #K2 #W #_ #H
elim (drops_inv_atom1 … H) -H #H destruct
-| #J #L1 #L2 #V #HL12 #IH #I #K2 #W #c #f #Hf #H
+| #J #L1 #L2 #V #HL12 #IH #b #f #I #K2 #W #Hf #H
elim (drops_inv_pair1_isuni … Hf H) -Hf -H *
[ #Hf #H destruct -IH
/4 width=4 by drops_refl, ex2_intro, or_introl/
elim (IH … Hg HLK2) -IH -Hg -HLK2 *
/4 width=4 by drops_drop, ex3_2_intro, ex2_intro, or_introl, or_intror/
]
-| #L1 #L2 #V1 #V2 #HL12 #IH #I #K2 #W #c #f #Hf #H
+| #L1 #L2 #V1 #V2 #HL12 #IH #b #f #I #K2 #W #Hf #H
elim (drops_inv_pair1_isuni … Hf H) -Hf -H *
[ #Hf #H destruct -IH
/4 width=4 by drops_refl, ex3_2_intro, or_intror/
(* Basic_2A1: includes: lsubr_fwd_drop2_abbr *)
lemma lsubr_fwd_drops2_abbr: ∀L1,L2. L1 ⫃ L2 →
- ∀K2,V,c,f. 𝐔⦃f⦄ → ⬇*[c, f] L2 ≡ K2.ⓓV →
- ∃∃K1. K1 ⫃ K2 & ⬇*[c, f] L1 ≡ K1.ⓓV.
-#L1 #L2 #HL12 #K2 #V #c #f #Hf #HLK2
+ ∀b,f,K2,V. 𝐔⦃f⦄ → ⬇*[b, f] L2 ≡ K2.ⓓV →
+ ∃∃K1. K1 ⫃ K2 & ⬇*[b, f] L1 ≡ K1.ⓓV.
+#L1 #L2 #HL12 #b #f #K2 #V #Hf #HLK2
elim (lsubr_fwd_drops2_pair … HL12 … Hf HLK2) -L2 -Hf // *
#K1 #W #_ #_ #H destruct
qed-.