Unsound variant of tshell-call-fn1 which doesn't take state.
Theorem: return-type-of-tshell-call-unsound-fn1
(defthm return-type-of-tshell-call-unsound-fn1 (b* (((mv status lines) (tshell-call-unsound-fn1 cmd print save))) (and (natp status) (string-listp lines))))