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17 include "datatypes/Nat.ma".
19 inductive NPlus (p:Nat): Nat → Nat → Prop ≝
20 | nplus_zero_2: NPlus p zero p
21 | nplus_succ_2: ∀q, r. NPlus p q r → NPlus p (succ q) (succ r).
23 interpretation "natural plus predicate" 'rel_plus x y z = (NPlus x y z).
25 notation "hvbox(a break ⊕ b break ≍ c)"
26 non associative with precedence 45
27 for @{'rel_plus $a $b $c}.