These too, are now assumed as postulates. All three of these congruence postulates are equivalent. You can assume any one of them, and prove the other two from there. See Congruence Of Triangles, Part II for a proof of this. The situation SSA is not a theorem or postulate, as it is often ambiguous, there are often two different non-congruent triangles with two congruent sides and a congruent angle at the end of one of the sides.
Numbers are equal.