#1 is definitely not meh, it's actually really practical if you're doing real work in Lisp. It seems meh if you're doing academic "basic CS concepts" exercises in Lisp, though.

> #3 re Python (and intial mention that languages arent written in themselves) just sounds like author is not up to date with modern python.

    Python 2.7.1 (r271:86832, Nov 27 2010, 18:30:46) [MSC v.1500 32 bit (Intel)] on win32
    Type "copyright", "credits" or "license()" for more information.
    
    >>> def foo():
    	x = 0
    	def bar(y):
    		x += y
    		return x
    	return bar
    
    >>> baz = foo()
    >>> baz(3)
    
    Traceback (most recent call last):
      File "<pyshell#10>", line 1, in <module>
        baz(3)
      File "<pyshell#7>", line 4, in bar
        x += y
    UnboundLocalError: local variable 'x' referenced before assignment

Is 2.7.1 not "modern" enough? I was under the impression that a lot of people are still on 2.7 rather than switching to Python 3. (I switched to Lua for scripting; it has working closures, lambdas, tail recursion, etc.)

the way original was worded it didn't sound like author was describing that particular wart, but, rather believing closures didn't exist. Generators, yield.

PyPy