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4 (* ||A|| A project by Andrea Asperti *)
6 (* ||I|| Developers: *)
7 (* ||T|| The HELM team. *)
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15 include "ground_2/notation/functions/oplus_4.ma".
16 include "ground_2/lib/list2.ma".
18 (* LISTS OF PAIRS ***********************************************************)
20 rec definition append2 A1 A2 (l1,l2:list2 A1 A2) on l1 ≝ match l1 with
22 | cons2 a1 a2 tl ⇒ {a1, a2} ⨮ append2 A1 A2 tl l2
25 interpretation "append (list of pairs)"
26 'OPlus A1 A2 l1 l2 = (append2 A1 A2 l1 l2).