The function process-alive-p
returns t
if process is alive, that is, if process-terminate has not been called on the process.
(mp:process-alive-p mp:*current-process*)
=> T
(let ((process (mp:process-run-function
"test" nil 'identity nil)))
(sleep 2)
(mp:process-alive-p process))
=> NIL
LispWorks User Guide and Reference Manual - 20 Sep 2017