Proof of `Stars are trees`
groundedproofs/Lax68Proofs/Relationships.lean · lax-68
What this proof establishes
no assumptions
thm✓
Lax68.StarTreeAssuming the claims on the left, the claim on the right holds — checked by the archive's pipeline. Proof code is not displayed here.
Description
A star is connected through its centre. A cycle would give a noncentral vertex two distinct neighbours, although its only neighbour is the centre.