As long as BlockSSALEFT TRUE, LEFT will be protected from evaluations and restorations by SSA. This is important to allow for (1) complex learning processes computing not just one but many correlated modifications of LEFT-columns, and (2) reward delays: using the EnableSSALEFT() instruction below, LEFT can influence when to trigger evaluations and when to wait for delayed reward.
EnableSSALEFT(): If (the value 10 is chosen arbitrarily) then set BlockSSALEFT FALSE.
EnableSSARIGHT(): analogous to EnableSSALEFT.