One who has a brother of any kind binds his brother's wife for yibum, and is [considered] his brother in all respects; except for someone who has [a brother] from a slave-woman or a non-Jewess.  One who has a son of any kind releases his father's wife from yibum, is liable for striking or cursing him, and is considered his son in every respect; except for someone who has [a son] from a slave-woman or a non-Jewess.