RE: What does "lacks a prefix" mean?

[Drew Adams]

> [Common Lisp] specifies that the bindings are done in parallel, but
> evaluation of the initialization forms is sequential. From
> http://www.lispworks.com/documentation/HyperSpec/Body/s_let_l.htm#let
> 
> "LET ... first evaluates the expressions init-form-1, init-form-2,
> and so on, in that order, saving the resulting values. Then all of
> the variables varj are bound to the corresponding values"

Good clarification.

> If the forms have no side effects, LET can indeed execute them in
> parallel, since there's no way to tell the difference. LET* can also
> do that for any initialization expressions that don't refer back to
> earlier variables and have no side effects.

Also well put.