F primes_upto(limit)
   V is_prime = [0B] * 2 [+] [1B] * (limit - 1)
   L(n) 0 .< Int(limit ^ 0.5 + 1.5)
      I is_prime[n]
         L(i) (n * n .< limit + 1).step(n)
            is_prime[i] = 0B
   R enumerate(is_prime).filter((i, prime) -> prime).map((i, prime) -> i)

F successive_primes(primes, diffs)
   [[Int]] results
   V dl = diffs.len

   L(i) 0 .< primes.len - dl
      V group = [0] * (dl + 1)
      group[0] = primes[i]
      L(j) i .+ dl
         I primes[j + 1] - primes[j] != diffs[j - i]
            L.break
         group[j - i + 1] = primes[j + 1]
      L.was_no_break
         results [+]= group

   R results

V prime_list = primes_upto(1'000'000)

print(‘For primes less than 1,000,000:-’)
L(diffs) [[2], [1], [2, 2], [2, 4], [4, 2], [6, 4, 2]]
   print(‘  For differences of #. ->’.format(diffs))
   V sp = successive_primes(prime_list, diffs)
   print(‘    First group   = ’sp[0])
   print(‘    Last group    = ’sp.last)
   print(‘    Number found  = ’sp.len)
   print()