qed.
lemma sle_skip_sle: ∀p. p ≤ ◊ → dx::p ≤ ◊.
-#p #H @(star_ind_l ??????? H) -p //
+#p #H @(star_ind_l … p H) -p //
#p #q #Hpq #_ #H @(sle_step_sn … H) -H /2 width=1/
qed.
qed.
lemma sle_nil_inv_in_whd: ∀p. p ≤ ◊ → in_whd p.
-#p #H @(star_ind_l ??????? H) -p // /2 width=3 by sprec_fwd_in_whd/
+#p #H @(star_ind_l … p H) -p // /2 width=3 by sprec_fwd_in_whd/
qed-.
lemma sle_inv_in_whd: ∀p. (∀q. p ≤ q) → in_whd p.
/2 width=1 by sle_nil_inv_in_whd/
qed-.
+
+lemma sle_fwd_in_whd: ∀p,q. p ≤ q → in_whd q → in_whd p.
+#p #q #H @(star_ind_l … p H) -p // /3 width=3 by sprec_fwd_in_whd/
+qed-.