Proof by Contradiction: The Infinitude of Twin Primes (BPN, Euclid, and Dirichlet)

1. Definitions and Notation:

We begin by establishing the core concepts and notation used throughout the proof.

• Prime Number Representation (mod6): Every integer can be written in one of the six forms when divided by 6: n≡0,1,2,3,4, or 5(mod6)

Exclude Multiples of 2 and 3:

• If n≡0(mod6), then n is divisible by 6.
• If n≡2(mod6), then n is divisible by 2.
• If n≡3(mod6), then n is divisible by 3.
• If n≡4(mod6), then n is divisible by 2.

Since any number that is divisible by 2 or 3 cannot be prime (except for 2 and 3 themselves), we can exclude these forms.

Remaining Forms:
n≡1(mod6)
n≡5(mod6)

Conclusion: The remaining possibilities for n that are not divisible by 2 or 3, and thus can be prime, are: n≡1(mod6) and n≡5(mod6). These forms can be rewritten as: n=6k+1 or n=6k+5. The second form can also be written as: n=6k−1(where k is an integer).

Thus, all prime numbers greater than 3 are of the form 6k±1.

• Prime Numbers: The set of all prime numbers is denoted by the symbol ℙ.
• Prime Candidate Sets A and B: We define two sets, A and B, that categorize potential prime number candidates based on their remainders when divided by 6:
  • A = {6k – 1 | k ∈ ℤ}
  • B = {6k + 1 | k ∈ ℤ}
  • Note 1: It’s key to remember that not every number within these sets is a prime number. They represent a pool of candidates from which prime numbers can be selected from our BPN Index. However, because all primes other than 2 and 3 are of form 6k±1, we are assured of complete coverage (other than 2 and 3) using this method. By definition, no number A OR B can contain a multiple of 2 and 3.
  • Note 2: A AND B contain reciprocal values, so that A=k(-1),k(1)=-7(A),5(A) and for B=k(-1),k(1)= -5(B),7(B), and so on for all values of A and B.
  • Note 3: By searching in only A AND B in the range 0 to N or only in |A| OR |B|, in the range -N to N, we can find all prime numbers in the range of 0 to N by identifying only numbers and composites of those forms, enhancing efficiency.
  • Note 4: By definition, an integer is prime if it cannot be expressed as two factors. So, if A OR B cannot be expressed as two integer factors A=xy or B=xy, then A OR B is prime.
    • If a number is of the form A OR B, and cannot be expressed as the form AA, AB, or BB; then A OR B is a prime number.
      • A prime number cannot be expressed as two integer variables: xy. If A or B could be expressed as xy, then A or B could not be a prime number. If A OR B is an integer and cannot be expressed xy, then A OR B is a prime number.
    • Further, (|A| OR |B|) BUT NOT (|A*A| OR |B*B|), then |A| OR |B| is a prime number, because |A| AND |B| have the same absolute values when considering a symmetrical range -N,N around 0; and AB is never a prime number by definition.
      • Thus, the sequence 1(B),5(A),7(B),11(A),13(B),17(A)… which is the start of sequence (A AND B) for positive values in the range 0 to N can also be extracted as: |A|=|…,-13(A),-7(A),-1(A),5(A),11(A),17(A),..| or B=|…,-17(B),-11(B),-5(B),1(B),7(B),13(B),…| when selecting a symmetrical range of -N to N for A OR B respectively.
  • Note 5: Logically, set of twin prime numbers greater than 3 and of the form p,p+2 must be of the form A AND B, since all primes greater than 3 are of the form A=6k-1 OR B=6k+1; and Ak+2=Bk and Bk-2=Ak.
    • So, if (A AND B) BUT NOT (AA OR AB OR BB), then A AND B are twin primes of the form p,p+2.
    • So, if ((|A(k)| AND |A(-k)|) OR (|B(k)| AND |B(-k)|)) BUT NOT (|AA(k,-k)| OR |BB(k,-k)|), then (|A(k)| AND |A(-k)|) OR (|B(k)| AND |B(-k)|) is also representative of a twin prime pair for A(k) AND B(k) using the symmetry of A AND B around 0.
• BPN Index: The Base Prime Notation (BPN) index, represented by I(p), provides a unique identifier sequence for each prime number candidate that is greater than 3 based on 6k±1 forms. This index is determined by the candidate prime’s membership in either set A or set B:
  • I(p) = (p + 1) / 6 if p ∈ A
  • I(p) = (p – 1) / 6 if p ∈ B

BPN Index	Original A Value	Absolute Value |A|	Composite?	Prime?
0	-1	1	No	No
1	5	5	No	Yes
2	-7	7	No	Yes
3	11	11	No	Yes
4	-13	13	No	Yes
5	17	17	No	Yes
6	-19	19	No	Yes
7	23	23	No	Yes
8	-25	25	Yes (index 1 * 1)	No
9	29	29	No	Yes
10	-31	31	No	Yes
11	35	35	Yes (index 1 * 2)	No
12	-37	37	No	Yes
13	41	41	No	Yes
14	-43	43	No	Yes
15	47	47	No	Yes
16	-49	49	Yes (index 2 * 2)	No
17	53	53	No	Yes
18	-55	55	Yes (index 1 * 3)	No
19	59	59	No	Yes
20	-61	61	No	Yes
21	65	65	Yes (index 1 * 4)	No
22	-67	67	No	Yes
23	71	71	No	Yes
24	-73	73	No	Yes
25	77	77	Yes (index 2 * 3)	No
26	-79	79	No	Yes
27	83	83	No	Yes
28	-85	85	Yes (index 1 * 5)	No
29	89	89	No	Yes
30	-91	91	Yes (index 2 * 4)	No
31	95	95	Yes (index 1 * 6)	No
32	-97	97	No	Yes
…∞	…∞	…∞	…∞	…∞

• Composite Factorization Set: For any composite number c belonging to either set A or set B, we define a set called the composite factorization set, denoted by F(c). This set contains information about the prime factors of c using their BPN indices:
  • F(c) = {(I(p), m) | p ∈ ℙ, p > 3, m ∈ ℤ⁺, p^m divides c}
  • Each element in this set is a pair (I(p), m). The first part, I(p), is the BPN index of a prime factor p of c. The second part, m, represents the multiplicity of p in the prime factorization of c (i.e., how many times p divides c).

2. Key Theorems:

Our proof relies on three foundational theorems in number theory:

• Euclid’s Theorem: This classic theorem establishes the infinitude of prime numbers. It states that there are infinitely many prime numbers. Formally: |ℙ| = ∞.
• Dirichlet’s Theorem on Arithmetic Progressions: This theorem guarantees an infinite supply of prime numbers within specific arithmetic sequences. It states that for any two integers, a and k, that are coprime (their greatest common divisor is 1), the arithmetic progression a + nk contains infinitely many prime numbers.
• Semiotic Prime Theorem: This theorem, derived from the properties of the BPN framework, provides a simple criterion for determining whether a number in set A or B is prime. It states that a number n in either set A or set B is a prime number if and only if its composite factorization set, F(n), is empty. This means that a prime number in these sets cannot have any other prime number from those sets as a factor.

Semiotic Prime Theorem: All prime numbers, except for 2 and 3, can be expressed as an element of either the set A = {6k + 5 | n ∈ ℤ} or the set B = {6k + 7 | p ∈ ℤ}, where:

• |A| = { |6k + 5| | n ∈ ℤ} represents the set of absolute values of elements in A.
• |B| = { |6k + 7| | p ∈ ℤ} represents the set of absolute values of elements in B.

Furthermore, these prime numbers cannot be expressed as the product of two elements from the same set. Therefore if |A| BUT NOT |A|*|A|; or |B| BUT NOT |B|*|B|, then |A| OR |B| is a prime number; and all prime numbers are in either |A| OR |B|; not just A AND B.

3. Gap Lemma

To analyze the spacing between prime numbers within our framework, we introduce a lemma specifically tailored to the properties of twin primes and BPN indices:

Lemma (Gap Lemma): Let p be a prime number belonging to set A, and let its BPN index be i. If the number p + 2 is composite, then the difference between p and any prime factor of p + 2 is strictly greater than 2. This holds true even when considering the combined contributions of all the prime factors of p + 2.

Proof of Gap Lemma:

• Index Difference: Let’s consider a prime factor of p + 2 that belongs to set B. Denote its BPN index as -j, where j is an odd integer. The difference between the BPN indices of p (index i) and this prime factor is i + j. Since i is even (as p is in set A) and j is odd, their sum i + j is odd.
• Gap Calculation: The difference between the prime number p and the prime number represented by the index -j is calculated as follows:
  • |p – (-6j + 1)| = |(6i – 1) – (-6j + 1)| = |6i + 6j| = 6|i + j|
  • Since i + j is odd, the absolute value |i + j| is also odd. This means that the gap, 6|i + j|, is a multiple of 6 but not a multiple of 12. Consequently, the gap is strictly greater than 2.
• Impossibility of a Gap of 2: For the gap to be exactly 2, the equation 6|i + j| – 2 = 2 would have to hold true. This would imply that 6|i + j| = 4. However, this is impossible because the left side of the equation, 6|i + j|, is always a multiple of 6, while 4 is not a multiple of 6.
• Considering Other Factors: Let’s examine the potential influence of other prime factors of p + 2. The product of the remaining factors (excluding those represented by indices j and -j) can be expressed as:
  • ∏_{(j′, m′) ∈ F(p+2), j′ ≠ -j} (6j′ ± 1)^{m′} = 6k ± 1, where k is an integer.
  • This expression reveals that multiplying any number of primes of the form 6k ± 1 always results in a product that is also of the form 6k ± 1.
  • Consequently, when this product is combined with the factors (6j + 1)ᵐ and (6(-j) – 1)ᵐ, the overall difference between p and any factor of p + 2 will remain a multiple of 6, plus or minus 2. It’s impossible to reduce this difference to precisely 2.

This concludes the proof of the Gap Lemma.

4. Proof by Contradiction

• Assumption: We start by assuming the opposite of what we want to prove. We assume there are only finitely many twin prime pairs. Formally: |{(p, p + 2) | p ∈ ℙ, p + 2 ∈ ℙ}| < ∞.
• Consequence 1: If there’s a finite number of twin primes, there must be a largest twin prime pair. Let’s represent this largest pair as (P, P + 2).
• Consequence 2: Because (P, P + 2) is the largest twin prime pair, no prime number greater than P + 2 can form a twin prime pair. This means that for all primes p > P + 2, there doesn’t exist another prime q such that the absolute difference between them is 2: |p – q| = 2.

5. Constructing a Contradiction

• Large Prime: Dirichlet’s Theorem guarantees that there are infinitely many prime numbers in the arithmetic progression 6k – 1 (which corresponds to the numbers in set A). Therefore, we can always find a prime number p in set A that is larger than P + 2. Let’s denote the BPN index of this prime as i: p = 6i – 1.
• Analyzing p + 2: Since p is in set A, the number p + 2 must belong to set B. We have two possibilities:
  • Case 1: p + 2 is prime: If p + 2 is prime, we’ve discovered a new twin prime pair (p, p + 2) where p is greater than P. This contradicts Consequence 1, which states that (P, P + 2) is the largest twin prime pair.
  • Case 2: p + 2 is composite: If p + 2 is not prime, it must be composite. We’ll now show that this case also results in a contradiction.

6. Applying the Gap Lemma

• In Case 2, where p + 2 is composite, the Gap Lemma comes into play. It tells us that the difference between p and any prime factor of p + 2 that comes from set B (even considering the combined effects of all prime factors) is strictly greater than 2.
• Because of this constraint, p + 2 cannot be a prime number. It’s impossible to create p + 2 by multiplying p with another prime that is only 2 units away.

7. Contradiction with Dirichlet’s Theorem

• Case 2 shows that for any prime number p greater than P + 2 within set A, the number p + 2 cannot be prime. This means that there are no twin primes beyond a certain point in the arithmetic progression 6k – 1, which is represented by set A.
• However, this directly contradicts Dirichlet’s Theorem. Dirichlet’s Theorem guarantees that there are infinitely many prime numbers within the arithmetic progression 6k – 1. If there were infinitely many primes in this progression, there would necessarily be infinitely many opportunities for twin primes to form.

8. Conclusion

Our initial assumption that there’s a finite number of twin prime pairs leads to a contradiction with fundamental theorems of number theory. Because the assumption leads to an impossible scenario, we conclude that the assumption must be false. Therefore, there must be infinitely many twin prime pairs.

Final Thoughts

This proof avoids relies solely on established theorems (Euclid’s Theorem, Dirichlet’s Theorem, and the Semiotic Prime Theorem). By combining the BPN framework with the Gap Lemma, we’ve demonstrated that the assumption of finitely many twin primes is incompatible with the infinite distribution of primes. This provides a logically sound and compelling argument for the infinitude of twin primes.

Appendix 1: Proof of Semiotic Prime Theorem

Semiotic Prime Theorem

Let:

• A={6x+5∣x∈Z}
• B={6y+7∣y∈Z}
• Define the product sets:
  • AA={(6x+5)(6y+5)∣x,y ∈ Z}
  • AB={(6x+5)(6y+7)∣x,y ∈ Z}
  • BB={(6x+7)(6y+7)∣x,y ∈ Z}

Then, any number that is an element of A or B but not an element of AA, AB, or BB is a prime number.

Proof by Contradiction

1. Assumption: Assume there exists a composite number k that is:
   • An element of either set A or B (i.e., of the form 6x+5 or 6y+7).
   • Not an element of AA, AB, or BB.
2. Case Analysis:
   • Case 1: k ∈ A (i.e., k=6x+5).
     • Subcase 1.1: k=(6x+1)(6y+1)→k ∈ AA
     • Subcase 1.2: k=(6x+1)(6y+5)→k ∈ AB
     • Subcase 1.3: k=(6x+5)(6y+5)→k ∈ AA
     • Subcase 1.4: k=(6x+5)(6y+1)→k ∈ AB
   • Case 2: k ∈ B (i.e., k=6y+7).
     • Subcase 2.1: k=(6x+1)(6y+1)→k ∈ BB
     • Subcase 2.2: k=(6x+1)(6y+7)→k ∈ AB
     • Subcase 2.3: k=(6x+7)(6y+7)→k ∈ BB
     • Subcase 2.4: k=(6x+7)(6y+1)→k ∈ AB
3. Contradiction:
   • In all subcases, k is shown to be an element of AA, AB, or BB. This contradicts the initial assumption that k is not an element of those sets.
4. Conclusion: Therefore, any number that is an element of A or B but not an element of AA, AB, or BB must be a prime number. This completes the proof.

Appendix 2 (unlikely to be accepted by GPT): Streamlined and Elegant Proof of the Infinitude of Twin Primes

1. Preliminaries

Define the sets A and B, which contain candidate primes based on their remainders when divided by 6:

• A = {6k – 1 | k ∈ ℤ}
• B = {6k + 1 | k ∈ ℤ}

2. Essential Theorems

• Euclid’s Theorem: There are infinitely many prime numbers.
• Dirichlet’s Theorem: For any coprime integers a and d, the arithmetic progression a + nd contains infinitely many primes.

3. Gap Lemma

Lemma: If p is a prime number belonging to set A, and p + 2 is composite, then the difference between p and any of its prime factors is strictly greater than 2.

Proof:

Let q be a prime factor of p + 2. Since p + 2 belongs to set B, the prime factor q must be an element of either set A or set B.

• Case: q ∈ A: This implies that q can be represented as 6k – 1 for some integer k. Since p is also in set A, we can express it as p = 6i – 1 for some integer i. The difference between p and q is:
  • |p – q| = |(6i – 1) – (6k – 1)| = 6|i – k|.
  • This difference is a multiple of 6, and therefore strictly greater than 2.
• Case: q ∈ B: This implies that q can be represented as 6k + 1 for some integer k. The difference between p (which is still 6i – 1) and q is:
  • |p – q| = |(6i – 1) – (6k + 1)| = |6(i – k) – 2|.
  • This difference is of the form 6n – 2 (where n = i – k), and it’s always greater than 2.

Therefore, regardless of whether q belongs to set A or set B, the difference between p and any prime factor of p + 2 is always strictly greater than 2.

4. Proof by Contradiction

• Assumption: Suppose, for the sake of contradiction, that there are only finitely many twin prime pairs. Let the largest twin prime pair be (P, P + 2).
• Consequence: This assumption implies that for every prime number p greater than P, the number p + 2 is not prime.
• Contradiction: Dirichlet’s Theorem guarantees that there are infinitely many prime numbers in the arithmetic progression 6k – 1 (represented by set A). This means we can always choose a prime number p from set A such that p > P.
  • Case 1: p + 2 is prime: This case directly contradicts our assumption, as we’ve found a twin prime pair (p, p + 2) larger than the assumed largest pair (P, P + 2).
  • Case 2: p + 2 is composite: In this case, the Gap Lemma tells us that the difference between p and any of its prime factors must be strictly greater than 2. This makes it impossible for p + 2 to be prime, as it cannot be formed by multiplying p with another prime that’s only 2 units away.
• Both Case 1 and Case 2 lead to contradictions.

5. Conclusion

Because the assumption that there are finitely many twin prime pairs leads to contradictions with established theorems, we conclude that our initial assumption must be false. Therefore, there must be infinitely many twin prime pairs.