def pairs_from_array(a):
  """
  Given an array of strings, create a list of pairs of elements from the array
  Creates all possible combinations without symmetry (given pair [a,b], it does not create [b,a])
  nor repetition (e.g. [a,a])
  :param a: Array of strings
  :return: list of pairs of strings
  """
  pairs = list()
  for i in range(len(a)):
    for j in range(len(a[i + 1 :])):
      pairs.append([a[i], a[i + 1 + j]])
  return pairs