-;;; Functional-env is the environment description for leaf, the lambda for
-;;; which we're computing a closure. This environment describes which of
-;;; lambda's vars we find in lambda's closure when it's running, versus finding
-;;; them on the stack. For each lambda-var in the functional environment's
-;;; closure list, if the lambda-var's home environment is the current
-;;; environment, then get a value off the stack and store it in the closure
-;;; we're computing. Otherwise that lambda-var's value comes from somewhere
-;;; else, but we have it in our current closure, the environment we're running
-;;; in as we compute this new closure. Find this value the same way we do in
-;;; LEAF-VALUE, by finding the lambda-var's position in the current
-;;; environment's description of the current closure.
+;;; A computed closure is a vector corresponding to the list of
+;;; closure variables described in an environment. The position of a
+;;; lambda-var in this closure list is the index into the closure
+;;; vector of values.