http://www.lispworks.com/documentation/lw50/CLHS/Body/d_opti...
Using types in Common Lisp:
https://lispcookbook.github.io/cl-cookbook/type.html
Not strongly and dynamically typed?
It has that plus optional static typing.
http://www.lispworks.com/documentation/lw50/CLHS/Body/d_opti...
Using types in Common Lisp:
https://lispcookbook.github.io/cl-cookbook/type.html