RE: What does "lacks a prefix" mean?

[Drew Adams]

> > And non-parallelizable theoretically :)
> 
> Regular let isn't parallelizable. It specifies that the value
> expressions are evaluated in order.
> 
> The only difference between the two is the environment within which
> later expressions are evaluated.

FWIW, Common Lisp specifies that "let performs the bindings
in parallel and let* does them sequentially."

That is theoretical, just a restatement that `let' bindings
are independent.  But it means that yes, they *could* be
evaluated in parallel (because they are independent).