[PD] trigger order of multiple env~ objects

[pix]

brain teaser for the day:

you have two env~ objects, listening to two different audio sources, and
you want to add the two resulting envelopes. the problem is, you need know
which env~ will output last during each frame so that you can attach it to
the first inlet of the + object. otherwise, you get the situation where
you are actually adding the envelope of the current frame of one signal to
the envelope of the previous frame of the other signal.

i don't think there is an answer (where "depends on creation order" ==
undefined == not an answer), but if there is one it would be nice.

pix