When a husband has died, and the couple had no children, the woman is known as a yevamah; the deceased man's surviving brother is known as a yavam; the mitzvah to marry her is called yibum. See P216.

When yibum is not performed, she is still not allowed to remarry unless chalitzah is performed, i.e. the yavam dons a specially made shoe on his right foot; then the yevamah from the yavam's foot, spits on the ground, and makes a verbal statement.

See note above.

See note above.

Deut. 25:9.

Bechoros 1:7.

From this expression, "the mitzvah of chalitzah," we see clearly that chalitzah counts as one of the mitzvos.

. That yibum is preferable to chalitzah.

. Rather than "Yevamos and Chalitzos," or something similar.