According to FMA manga...
I think, that`s what right: what remains after Envy`s
reconstruction is dissappearing. Remember the moment,
when Envy`s changed into Lan Fan and then Gluttony
swallowed him? The good piece of Envy has remained:
a half!!! And in the scenes, where Gluttony and Al
talking, there`s no sight of that half of the body.
I think, there`re more examples, but i can`t remember...
Now, the FMA series...
Scene (near end), where Envy-Hughes attackes Ed with
that small knives. There`s no sight of them later as well.
And i like Nepharski`s
theory about mass reorganisation.
Envy must have really superhuman strength to care such a mass -
just look at him "breakdancing" during the fight with Greed!!!
HA! Therefore, Envy can cheat in the shops!!!
Because the parts, he leaves, disappear not instantly.
Envy: Hello, i`ll take these nice things. Here`s the money.
Bye-bye! (walks away)
Shopkeeper (10 seconds later): You bastard! Police!!!