qed.
lemma fsle_bind_dx_dx: ∀L1,L2,T1,T2. ❪L1,T1❫ ⊆ ❪L2.ⓧ,T2❫ → |L1| ≤ |L2| →
∀p,I,V2. ❪L1,T1❫ ⊆ ❪L2,ⓑ[p,I]V2.T2❫.
#L1 #L2 #T1 #T2 * #n1 #x1 #f2 #g2 #Hf2 #Hg2 #H #Hfg2 #HL12 #p #I #V2
elim (lveq_inv_void_dx_length … H HL12) -H -HL12 #m1 #HL12 #H1 #H2 destruct
qed.
lemma fsle_bind_dx_dx: ∀L1,L2,T1,T2. ❪L1,T1❫ ⊆ ❪L2.ⓧ,T2❫ → |L1| ≤ |L2| →
∀p,I,V2. ❪L1,T1❫ ⊆ ❪L2,ⓑ[p,I]V2.T2❫.
#L1 #L2 #T1 #T2 * #n1 #x1 #f2 #g2 #Hf2 #Hg2 #H #Hfg2 #HL12 #p #I #V2
elim (lveq_inv_void_dx_length … H HL12) -H -HL12 #m1 #HL12 #H1 #H2 destruct