(get-in [[4 5] [6 7]] [0] 42) # => (4 5) (get-in [[4 5] [6 7]] [0 1] 42) # => 5 (get-in [[4 5] [6 7]] [-1] 42) # => 42 (get-in [[4 5] [6 7]] [9 9 9] 42) # => 42