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Lax68.TreeOuterplanar

Trees are outerplanar

concepts/Lax68/TreeOuterplanar.lean · lax-68

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    Theorem

    Every tree is outerplanar.

    Lean source view on GitHub

    1import Lax68.Trees
    2import Lax68.Outerplanar
    3
    4/-!
    5---
    6title: Trees are outerplanar
    7type: theorem
    8---
    9Every tree is outerplanar.
    10-/
    11
    12set_option autoImplicit false
    13
    14namespace Lax68.TreeOuterplanar
    15
    16axiom tree_outerplanar {V : Type*} {G : SimpleGraph V} :
    17 Lax68.Trees.IsTree G →
    18 Lax68.Outerplanar.IsOuterplanar G
    19
    20end Lax68.TreeOuterplanar
    21

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