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Copyright 2026 The Formal Conjectures Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
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-/
import FormalConjecturesUtilDubner's conjecture
namespace DubnerConjecture
A twin prime is a prime number that has a prime gap of 2, meaning either p - 2 or p + 2 is also prime.
def IsTwinPrime (p : ℕ) : Prop :=
p.Prime ∧ ((p - 2).Prime ∨ (p + 2).Prime)
@[category test, AMS 11]
theorem t1 : ¬IsTwinPrime 2 := ⊢ ¬IsTwinPrime 2
All goals completed! 🐙
@[category test, AMS 11]
theorem t2 : IsTwinPrime 3 := ⊢ IsTwinPrime 3
All goals completed! 🐙
@[category test, AMS 11]
theorem t3 : IsTwinPrime 5 := ⊢ IsTwinPrime 5
All goals completed! 🐙
@[category test, AMS 11]
theorem t4 : IsTwinPrime 101 := ⊢ IsTwinPrime 101
All goals completed! 🐙
@[category test, AMS 11]
theorem t5 : ¬IsTwinPrime 100 := ⊢ ¬IsTwinPrime 100
All goals completed! 🐙
Every even number greater than 4208 is the sum of two twin primes.
@[category research open, AMS 11]
theorem dubner_conjecture (n : ℕ) (hn : 4208 < n) (h : Even n) :
∃ p q : ℕ,
IsTwinPrime p ∧
IsTwinPrime q ∧
p + q = n := n:ℕhn:4208 < nh:Even n⊢ ∃ p q, IsTwinPrime p ∧ IsTwinPrime q ∧ p + q = n
All goals completed! 🐙
end DubnerConjecture