I think you missed /my/ point. What happens when you "remove the cruft" (parentheses) from the following:

    (defun example ()
      (ascertain that (+ 1 1) is 2)
      (ascertain that (+ 1 1) is not zero)
      (ascertain that 0 is not zero)
      (ascertain that 0 is zero)
      (ascertain that (+ 2 2) is 5)
      (ascertain that (+ 2 2) is not 5)
      (ascertain that (+ 2 2) is = 4.0)
      (ascertain that (+ 1 1) is member of '(1 2 3))
      (ascertain that 0 is a member of '(1 2 3))
      (ascertain that pi is not a member of '(foo bar zot pi))
      (ascertain that (error "blah") signals simple-error)
      (ascertain that (error "blah") signals a serious-condition)
      (ascertain that (error 'unexpected-result) signals an unexpected-result))

Does it look like Python?