Yes, this is a mistake in the problem description. The action
descriptions should be:
Action(Left, PRECOND: AtR, EFFECT: (AtL ∧ ¬AtR) ∨ AtR
Action(Right, PRECOND: AtL, EFFECT: (AtR ∧ ¬AtL) ∨ (AtR ∧ ¬AtL ∧ when CleanL : ¬CleanL))
Action(Suck, PRECOND:, EFFECT: (when AtL : CleanL) ∧ (when AtR : CleanR))
Note, on some web browsers, the AND and OR symbols (wedges and vees) may not appear in the action descriptions above. If you do not see them, then try another browser.