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4 (* ||A|| A project by Andrea Asperti *)
6 (* ||I|| Developers: *)
7 (* ||T|| The HELM team. *)
8 (* ||A|| http://helm.cs.unibo.it *)
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15 include "basic_2/grammar/leq.ma".
17 (* EQUIVALENCE FOR LOCAL ENVIRONMENTS ***************************************)
19 (* Main properties **********************************************************)
21 theorem leq_trans: ∀d,e. Transitive … (leq d e).
22 #d #e #L1 #L2 #H elim H -L1 -L2 -d -e
23 [ #d #e #X #H lapply (leq_inv_atom1 … H) -H
25 | #I1 #I #L1 #L #V1 #V #_ #IHL1 #X #H elim (leq_inv_zero1 … H) -H
26 #I2 #L2 #V2 #HL2 #H destruct /3 width=1 by leq_zero/
27 | #I #L1 #L #V #e #_ #IHL1 #X #H elim (leq_inv_pair1 … H) -H //
28 #L2 #HL2 #H destruct /3 width=1 by leq_pair/
29 | #I1 #I #L1 #L #V1 #V #d #e #_ #IHL1 #X #H elim (leq_inv_succ1 … H) -H //
30 #I2 #L2 #V2 #HL2 #H destruct /3 width=1 by leq_succ/