I'm curious too. Conceptually, `let` defines a function of n variables and then invokes it on a list of n values:

    (let ((a 3)
          (b 5)
          (c -1))
      (* a (+ b c)))

    def «gensym»(a,b,c):
        return (a * (b + c))
    «the-gensym»(3,5,-1)

It seems workable purely in terms of the code transformation. But, I haven't tried.