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Each question has a "Toggle Solution" button -- click it to reveal that question's solution.
Environment Diagrams
Question 1
def f(x):
return lambda y: x(y)
def g(x):
return lambda : f(x) + f(y)
y = 2
result = f(g(f))Question 2
def always_roll(n):
return lambda s0, s1: n
def make_bad_strategy(p):
def strategy(s0, s1):
# next line is bad style!
return always_roll(1 - p)(s0, s1)
return strategy
num_rolls = make_bad_strategy(1)(50, 50)Question 3
def test(fn):
def new_fn(x):
if x > 10:
return new_fn(x % 10)
else:
return fn(x)
return new_fn
x = 10
new = test(lambda score: score - x)
new(42)Question 4
x = 4
def foo(foo):
def bar(y):
y += foo
return lambda : y + x
foo += 3
return bar
x = 5
foo(5)(4)()Question 5
def dream1(f):
kick = lambda x: mind()
def dream2(secret):
mind = f(secret)
kick(2)
return dream2
inception = lambda secret: lambda: secret
real = dream1(inception)(42)Question 6
def albert(albert):
albert = albert()
def albert():
albert = lambda albert: albert
return albert(albert)
return albert
albert(lambda: albert)()