Common Lisp Extensions. Node: Variable Bindings
Generalized Variables
Control Structure
Conditionals
5.3: Variable Bindings
These Lisp forms make bindings to variables and function names,
analogous to Lisp's built-in let form.
See Modify Macros, for the letf and letf* forms which
are also related to variable bindings.
Generalized Variables
Control Structure
Conditionals