> (with ((a b c d) nil)
  >     (= a (fn () ...))
  >     (= b (fn () ...))
  >     (= c (fn () ...))
  >  ...)

If it's an idiom, probably needs a macro for it then ^^

  (mac with-r (vars . body)
    (let vars (pair vars)
      `(let ,(map car vars) nil
         ,@(map [let (var val) _ `(= ,var ,val)] vars)
         ,@body)))