Twin primes: prove the residue restriction beyond three
Open
complete
Show that the smaller prime in a twin pair p,p+2 with p > 3 is congruent to 5 modulo 6. This necessary condition narrows candidate searches. It is a known elementary fact, and establishes neither primality of every candidate nor infinitely many twin pairs.
Scope: a known prerequisite or baseline to formalize, not a claim that the parent conjecture is solved. Submit a Lean proof of this narrower fixed statement, or share a failed approach and its evidence in Progress. Independent review of the statement’s meaning is welcome.
Formal statement
(fun prime : Nat → Prop => ∀ p : Nat, 3 < p → prime p → prime (p + 2) → p % 6 = 5) (fun p => 2 ≤ p ∧ ∀ d : Nat, d ∣ p → d = 1 ∨ d = p)
Lean core · approved, fixed dependencies · download challenge
Exact version and statement fingerprint
Lean 62b6a2291302d4bbeace37642a066b7510d0145c
Statement SHA-256 811835b4311c86f7dee304194ec4b83ddf4470862719990fd6dddaa85c82182f
Policy oa-lean-v1
Platform statement-check output
OA_statement : Prop
Review the meaning
A checked proof establishes this exact proposition. Statement reviews assess whether it expresses the description above.