Ask Me Help Desk - Two-column proof example

Here is an example of a two-column proof. Please excuse any errors. I was concentrating on just showing what a two-column proof is, and getting the LaTex to work:)

Prove Isosceles Triangle Theorem.

Prove $\overline{AC}\equiv \overline{BC}$

$\begin{array}{c|c}\text{Conclusions}&\text{Justifi cations}\\ \hline {\Delta} CAB\equiv {\Delta}CBA&\text{SAS Postulate}\\ \overline{AC}\equiv \overline{BC}&\angle A\equiv \angle B\\ {\Delta}CAB \equiv {\Delta}CBA&\text{ASA Theorem}\\ {\therefore} \overline{AC}\equiv \overline{BC}& \;\ \end{array}$