“A if and only if B”, written symbolically as , is defined by the truth table:
\hline
A & B & A \iff B\\
\hline
T & T & T\\
T & F & F\\
F & T & F\\
F & F & T\\
\hline
\end{array}
Thus, is only true when and have the same truth values.
“A if and only if B”, written symbolically as , is defined by the truth table:
Thus, is only true when and have the same truth values.