+
+definition init_copy ≝
+ seq ? init_current_on_match
+ (seq ? (move_r ?)
+ (seq ? (adv_to_mark_r ? (is_marked ?))
+ (adv_mark_r ?))).
+
+definition R_init_copy ≝ λt1,t2.
+ ∀l1,l2,c,ls,d,rs.
+ no_marks l1 → no_grids l1 →
+ no_marks l2 → is_grid c = false →
+ t1 = midtape STape (l1@〈c,false〉::〈grid,false〉::ls) 〈grid,false〉 (l2@〈comma,true〉::〈d,false〉::rs) →
+ t2 = midtape STape (〈comma,false〉::(reverse ? l2)@〈grid,false〉::l1@〈c,true〉::〈grid,false〉::ls) 〈d,true〉 rs.
+
+lemma list_last: ∀A.∀l:list A.
+ l = [ ] ∨ ∃a,l1. l = l1@[a].
+#A #l <(reverse_reverse ? l) cases (reverse A l)
+ [%1 //
+ |#a #l1 %2 @(ex_intro ?? a) @(ex_intro ?? (reverse ? l1)) //
+ ]
+qed.
+
+lemma sem_init_copy : Realize ? init_copy R_init_copy.
+#intape
+cases (sem_seq ????? sem_init_current_on_match
+ (sem_seq ????? (sem_move_r ?)
+ (sem_seq ????? (sem_adv_to_mark_r ? (is_marked ?))
+ (sem_adv_mark_r ?))) intape)
+#k * #outc * #Hloop #HR
+@(ex_intro ?? k) @(ex_intro ?? outc) % [@Hloop] -Hloop
+#l1 #l2 #c #ls #d #rs #Hl1marks #Hl1grids #Hl2marks #Hc #Hintape
+cases HR -HR
+#ta * whd in ⊢ (%→?); #Hta lapply (Hta … Hl1grids Hc Hintape) -Hta -Hintape #Hta
+* #tb * whd in ⊢ (%→?); #Htb lapply (Htb … Hta) -Htb -Hta
+generalize in match Hl1marks; -Hl1marks cases (list_last ? l1)
+ [#eql1 >eql1 #Hl1marks whd in ⊢ ((???%)→?); whd in ⊢ ((???(????%))→?); #Htb
+ * #tc * whd in ⊢ (%→?); #Htc lapply (Htc … Htb) -Htc -Htb *
+ [* whd in ⊢ ((??%?)→?); #Htemp destruct (Htemp)]
+ * #_ #Htc lapply (Htc … (refl …) (refl …) ?)
+ [#x #membx @Hl2marks @membx]
+ #Htc whd in ⊢ (%→?); #Houtc lapply (Houtc … Htc) -Houtc -Htc #Houtc
+ >Houtc %
+ |* #c1 * #tl #eql1 >eql1 #Hl1marks >reverse_append >reverse_single
+ whd in ⊢ ((???%)→?); whd in ⊢ ((???(????%))→?);
+ >associative_append whd in ⊢ ((???(????%))→?); #Htb
+ * #tc * whd in ⊢ (%→?); #Htc lapply (Htc … Htb) -Htc -Htb *
+ [* >Hl1marks [#Htemp destruct (Htemp)] @memb_append_l2 @memb_hd]
+ * #_ >append_cons <associative_append #Htc lapply (Htc … (refl …) (refl …) ?)
+ [#x #membx cases (memb_append … membx) -membx #membx
+ [cases (memb_append … membx) -membx #membx
+ [@Hl1marks @memb_append_l1 @daemon
+ |>(memb_single … membx) %
+ ]
+ |@Hl2marks @membx
+ ]]
+ #Htc whd in ⊢ (%→?); #Houtc lapply (Houtc … Htc) -Houtc -Htc #Houtc
+ >Houtc >reverse_append >reverse_append >reverse_single
+ >reverse_reverse >associative_append >associative_append
+ >associative_append %
+qed.
+
+(* OLD