• L = [56,29,35,42,15,41,75,21]

• LC = [35]

• L1 = [15,21,29], recursively sort L1:
  • L = [15,21,29]
  • LC = [21]
  • L1 = [15]
  • L2 = [29]
  • join L1' LC L2' = [15,21,29]

• L2 = [56,42,41,75], recursively sort L2:
  • L = [56,42,41,75]
  • LC = [42]
  • L1 = [41].
  • L2 = [56,75]. Recursively sort L2:
    • L = [56,75]
    • LC = [56]
    • L1 = []
    • L2 = [75]
    • join L1' LC L2' = [56,75]
    L2' = [56,75]
  • join L1' LC L2' = [41,42,56,75]
  L2' = [41,42,56,75]

• join L1' LC L2' = [15,21,29, 35 ,41,42,56,75]