How is priority determined between two claims of prior ownership when the evidence for the earlier claim does not negate the evidence for the later claim?

Primary text

If a person claims a house in another's possession has been theirs for one year, supported by evidence, and a third party subsequently claims they purchased it from the first claimant two years ago, supported by their own evidence, the right of the second claimant (the one claiming ownership from two years ago) is established. The first claimant's evidence stating ownership for one year does not invalidate the claim of two years of ownership, as there is no contradiction between owning something for two years and owning it for one year; the owner of two years maintains ownership in the second year. If the evidence for the two-year purchase explicitly states the seller was the owner, ownership is established without dispute. If it does not explicitly state ownership, there is a difference of opinion among jurists.