פירוש על בבא בתרא 56:2

That is not accompanied by a claim - Explained in the Mishna later (Bava Batra page 41a), says to him "what are you doing within mine (in my property)", (the trespasser) says to him that "Nobody ever told me anything (about me using your property)", and does not say to him, "you sold it to me".

Should be chazaka - That is (since) you said that three years takes out from him, from the dominion of the seller. (without any need of claiming legal ownership)