(* Properties on local environment slicing ***********************************)
-(* Basic_1: includes: wcpr0_drop *)
lemma lpr_drop_conf: ∀G. dropable_sn (lpr G).
/3 width=6 by lpx_sn_deliftable_dropable, cpr_inv_lift1/ qed-.
-(* Basic_1: includes: wcpr0_drop_back *)
lemma drop_lpr_trans: ∀G. dedropable_sn (lpr G).
/3 width=10 by lpx_sn_liftable_dedropable, cpr_lift/ qed-.