The compounds of formula Iin which A, R1, R2 and R3 have the meanings as given in the description, are novel effective PDE4 inhibitors. User behavior is monitored as to the search queries, the search results, or both. When the latch stops at the first position, it also latches onto an operational interface or a mechanism component so as to prevent the user from electrically or mechanically operating the apparatus. A lower surface of the capping layer and an upper surface of the CTM electrode meet at an interface.