Proof of `Triangles are planar`

groundedproofs/Lax68Proofs/Relationships.lean · lax-68

What this proof establishes

Assuming the claims on the left, the claim on the right holds — checked by the archive's pipeline. Proof code is not displayed here.

Read the Lean proof on GitHub

Description

Triangles are outerplanar, and outerplanar graphs are planar.