It may turn out to be a piece of one of Mrs. Inglethorp's own dresses, and quite unimportant. 
There is no chance that this could be from Mrs. Inglethorp's dress.
mnli hypothesis: There is no chance that this could be from Mrs. Inglethorp's dress. premise: It may turn out to be a piece of one of Mrs. Inglethorp's own dresses, and quite unimportant. 