Sentence:  Thus , while it remains possible that the Babylonians and / or the Pythagoreans may perhaps have had the magic square of three before the Chinese did , more definite evidence will have to turn up from the Middle East or the Classical World before China can <WSD>lose</WSD> her claim to the earliest known magic square by more than a thousand years . 
Meaning of the word marked with <WSD> tags:  fail to keep or to maintain; cease to have, either physically or in an abstract sense