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Diffstat (limited to 'AvlVerification/Tree.lean')
-rw-r--r-- | AvlVerification/Tree.lean | 81 |
1 files changed, 0 insertions, 81 deletions
diff --git a/AvlVerification/Tree.lean b/AvlVerification/Tree.lean deleted file mode 100644 index 8a043a1..0000000 --- a/AvlVerification/Tree.lean +++ /dev/null @@ -1,81 +0,0 @@ -import «AvlVerification» - -namespace Tree - -variable {T: Type} - -open avl_verification - --- Otherwise, Lean cannot prove termination by itself. -@[reducible] -def AVLTree (U: Type) := Option (AVLNode U) -def AVLTree.nil: AVLTree T := none - -def AVLTree.val (t: AVLTree T): Option T := match t with -| none => none -| some (AVLNode.mk x _ _) => some x - -def AVLTree.left (t: AVLTree T): AVLTree T := match t with -| none => none -| some (AVLNode.mk _ left _) => left - -def AVLTree.right (t: AVLTree T): AVLTree T := match t with -| none => none -| some (AVLNode.mk _ _ right) => right - -def AVLNode.left (t: AVLNode T): AVLTree T := match t with -| AVLNode.mk _ left _ => left - -def AVLNode.right (t: AVLNode T): AVLTree T := match t with -| AVLNode.mk _ _ right => right - -def AVLNode.val (t: AVLNode T): T := match t with -| AVLNode.mk x _ _ => x - -mutual -def AVLTree.height_node (tree: AVLNode T): Nat := match tree with -| AVLNode.mk y left right => 1 + AVLTree.height left + AVLTree.height right - -def AVLTree.height (tree: AVLTree T): Nat := match tree with -| none => 0 -| some n => 1 + AVLTree.height_node n -end - -def AVLTreeSet.nil: AVLTreeSet T := { root := AVLTree.nil } - --- Automatic synthesization of this seems possible at the Lean level? -instance: Inhabited (AVLTree T) where - default := AVLTree.nil - -instance: Inhabited (AVLTreeSet T) where - default := AVLTreeSet.nil - -instance: Coe (Option (AVLNode T)) (AVLTree T) where - coe x := x - --- TODO: ideally, it would be nice if we could generalize --- this to any `BinaryTree` typeclass. - -def AVLTree.mem (tree: AVLTree T) (x: T) := - match tree with - | none => False - | some (AVLNode.mk y left right) => x = y ∨ AVLTree.mem left x ∨ AVLTree.mem right x - -@[simp] -def AVLTree.mem_none: AVLTree.mem none = ({}: Set T) := rfl - -@[simp] -def AVLTree.mem_some {x: T} {left right: AVLTree T}: AVLTree.mem (some (AVLNode.mk x left right)) = (({x}: Set T) ∪ AVLTree.mem left ∪ AVLTree.mem right) := by - ext y - rw [AVLTree.mem] - simp [Set.insert_union] - simp [Set.insert_def, Set.setOf_set, Set.mem_def, Set.union_def] - --- TODO(reinforcement): ∪ is actually disjoint if we prove this is a binary search tree. - -def AVLTree.set (t: AVLTree T): Set T := _root_.setOf (AVLTree.mem t) - -@[simp] -def AVLTree.set_some {x: T} {left right: AVLTree T}: AVLTree.set (some (AVLNode.mk x left right)) = {x} ∪ AVLTree.set left ∪ AVLTree.set right := sorry - -end Tree |