•1. TrCl
\subseteq NLOGSPACE
•
•Lemma.
Denote PosTrCl the language where trcl is used only in positive
positions (under even number of negations). Then:
PosTrCL +
< = TrCl + <
•You proved it already in 531 ! Plus: recall how inflationary datalog expresses not TC.