Find a natural number n such that n+1, n+11, n+111 are all primes.
Trying 2 as a first even number we get an answer.
To qualify for d1 or d2 I will rephrase the question:
Prove that there is only one natural number n such that n+1, n+11, n+111 are all primes.
FOR n>2 t
The three addends are distinct members of the set (1,2,3) therefore at least one of them is divisible by 3 and therefore cpomposite.