An implementation of McCulloch's machine from Smullyan's book "What Is the Name of This Book?"

mcculloch.py

from   re  import  match  as  _m
calcule=(lambda n,machine='machi'
'ne-1': (        lambda m:(lambda
f:(lambda         x: x(x))(lambda
x:f(lambda v:      (x(x ))(v))))(
lambda f:lambda     x:(lambda r:r
.group(1) if r       else m[1][x[
0]](f(x[1:]))        )(_m(m[0],x)
))(n) if _m(          r'[{}]*{}'.
format( ''.            join(m[1])
,m[0]),n)      else     None)({''
'machin'      'e-1':     (r'2([1'
r'-9]+'      r')$' ,      {'3''':
lambda      y:y+'2'+y         ,''
'4':      lambda y:y[:        :-1
],      '5':lambda y:2*      y}),
'machine-2':(r'2([1-9]+)2$',{'6':
lambda y:'2'+y,'4':lambda y:y[::-
1],'5':lambda y:y*2})}[machine]))