>>> def minelem(lst, i=0, length=None, acc=None):
...     if length is None:
...         length = len(lst)
...     if i == length:
...         return acc
...     if acc is None:
...         acc = lst[0]
...     if lst[i] < acc:
...         return minelem(lst, i + 1, length, lst[i])
...     else:
...         return minelem(lst, i + 1, length, acc)
... 
>>> minelem([])
>>> minelem([1])
1
>>> minelem([1, 2])
1
>>> minelem([2, 1])
1
>>> minelem([5, 4, 1, 2, 7, 6])
1
>>> minelem([3, 2, 1])
1
>>>

  
>>> def nummirror(n, acc=0):
...     if n == 0:
...         return acc
...     else:
...         return nummirror(n // 10, acc * 10 + n % 10)
... 
>>> nummirror(1)
1
>>> nummirror(12)
21
>>> nummirror(21)
12
>>> nummirror(123)
321
>>> nummirror(1234)
4321
>>>