Rintanen, J. (1999)
"Constructing Conditional Plans by a Theorem-Prover",
Volume 10, pages 323-352.
Theorem 2 is correct but the preceding discussion on page 326 makes false
claims about it.
Contrary to what is claimed, the theorem does not say anything about
conditional plans of polynomial size.
It only shows that the existence of conditional plans
with executions of polynomial length is Pip2-hard.