Church

ip = get_ipython()
ip.display_formatter.formatters.keys()
text_formatter = ip.display_formatter.formatters['text/plain']

pnum = lambda n: n(lambda x: x + 1)(0)

def _ppf(arg, p, cycle):
    """
    Pretty print a functions
    """
    if arg.__name__ == '<lambda>':
        try:
            i = pnum(arg)
            if isinstance(i, int):
                arg.__name__ = '_{}'.format(i)
        except:
            pass

    p.text(arg.__name__)

text_formatter.for_type(type(lambda:1), _ppf);

I  = lambda a: a                             ; I.__name__  = 'Identity'
K  = lambda a: lambda b: a                   ; K.__name__  = 'Kestral'
KI = K(I)                                    ; KI.__name__ = 'Kite'
B  = lambda f: lambda g: lambda a: f(g(a))   ; B.__name__  = 'Bluebird'
M  = lambda f: f(f)                          ; M.__name__  = 'Mockingbird'
Th = lambda f: lambda g: g(f)                ; Th.__name__ = 'Thrush'
Y  = lambda f: f(M)(f(M))                    ; Y.__name__  = 'Y'

T   = lambda x: lambda y: x                  ; T.__name__ = 'T'
F   = lambda x: lambda y: y                  ; F.__name__ = 'F'
NOT = lambda x: x(F)(T)
OR  = lambda x: lambda y: x(x)(y)
AND = lambda x: lambda y: x(y)(x)

INC = lambda n: lambda f: B(f)(n(f))
ADD = lambda n: n(INC)
MUL = B
POW = Th

_0  = lambda f: lambda a: a
_1  = INC(_0)
_2  = ADD(_1)(_1)
_3  = INC(_2)
_4  = ADD(_3)(_1)
_5  = ADD(_3)(_2)
_6  = MUL(_2)(_3)
_7  = ADD(POW(_2)(_2))(_3)
_8  = POW(_2)(_3)
_9  = POW(_3)(_2)
_10 = INC(_9)