(* DELAYED FOCUSED REDUCTION ************************************************)
-lemma dfr_lift_bi (f) (p) (q) (t1) (t2): ÆŽt1 â
+lemma dfr_lift_bi (f) (p) (q) (t1) (t2): t1 Ïĩ ð â
t1 âĄðð[p,q] t2 â â[f]t1 âĄð[âp,âq] â[f]t2.
-#f #p #q #t1 #t2 #Ht1
-* -t2 #b #Hr #Hb
+#f #p #q #t1 #t2 #H0t1
+* #b * #Hb #Ht1 #Ht2
+@(ex_intro âĶ (âb)) @and3_intro
+[ //
+| lapply (in_comp_lift_bi f âĶ Ht1) -Ht1 #Ht1
+
+
+
+
+