If it rolled beyond the techum, or a heap fell on it, or it burned, or [it was] terumah which became contaminated — if it was still day, the eruv is invalid; if after dark, the eruv is valid. If it is in doubt — R’ Meir and R’ Yehudah say: He is caught in between. R’ Yose and R’ Shimon say: A doubtful eruv is valid. Said R’ Yose: Avtulmos attested in the name of five sages that a doubtful eruv is valid.