-lemma pippo: ∀M,v1,v2,d,i. [i⬐d] v1 ≐⦋M⦌ v2 → v1 ≐⦋M⦌ ↓[i,1] v2.
-#M #v1 #v2 #d #i #H #j elim (lt_or_ge … j i) #Hij
-[ >lower_lt // <(H j) >raise_lt //
-| >lower_ge // <(H (j+1)) >raise_gt /2 width=1 by le_S_S/
-]
-qed-.
+(* Note: sort evaluation *)
+ sv: nat → dd;
+
+(* Note: interpretation: sort *)
+ ms: ∀gv,lv,s. ⟦⋆s⟧{M}[gv, lv] ≗ sv M s;