*****PEREK #4 HA'CHOLETZ L'YEVIMTO*****
7) [line 9] SAFEK BEN TISH'AH LA'RISHON O BEN SHIV'AH LA'ACHARON - If a woman remarried within three months of her previous marriage and gave birth six months later, we are in doubt if the baby born is the son of the first husband after a full gestation period, or if he is the premature baby of the second husband. The Gemara is discussing a case where we have a doubt whether the child that is born is the son of the dead brother (in which case Yibum was prohibited), or of the Yavam (in which case it was a valid Yibum.)
8) [line 11] ASHAM TALUY
The Korban Asham Taluy is a ram worth two Sela'im that is offered when a person is in doubt as to whether he committed a transgression for which he must bring a Korban Chatas (Vayikra 5:17-19). If he later discovers that he did indeed sin, he must offer a Korban Chatas; the Asham Taluy only provides temporary atonement during the period of doubt.
Index to Background for Maseches Yevamos