Only I had a key to that door, the door was unlocked earlier, the <e1>key</e1> was locked in a <e2>safe</e2> and only I had access to the key.
Only I had a
Only I had a key to that door, the door was unlocked earlier, the key was locked in a safe and only I had access to the key.
<triplet> key <subject> safe <object> Content-Container(e1,e2)