This is a sentence from the Tanaka corpus, I would have thought that it means
"I have a parent that has passed away.".

I'm asking that because the Tanaka corpus contains some mistakes so I think it
may be the case here but I'm not sure(some people say that this sentence
doesn't mean anyone is dead).
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2019-01-09T12:51:15.830
64804
2022-05-21T01:48:25.827
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question
meaning
Does 両親ともに健在とは限らない。mean "Both of my parents aren't alive."?
It's correcting someone or himself's say because that might be too early to
judge that. Like, when you look at a shore and see a storm coming soon, but
you shouldn't know about a shore which is located in hundreds miles away. I
think the phrase とは限らない is used in a case when you're not clear about that.
Sometimes it'd sound too cautious.
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2019-01-09T14:16:51.200
64806
2019-01-09T14:23:20.203
2019-01-09T14:23:20.203
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answer
Strictly speaking, "〜とは限らない" means that there is not a 100% probability that
the thing is true. However, it is used when there is no guarantee that the
thing is 100% sure, but there is a slight probability that the thing is true.

In this case, it means that there is not a 100% probability that the parents
are still alive and well.

In other words, **there is no guarantee that the 〇〇 will happen.**

Example①：（Often used in Manga.） ・彼が絶対に生きているとは限らない

Example2②（when you are not sure if the bus will be on time） ・バスが時間通りに来るとは限らない
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2022-05-21T01:48:25.827
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answer