# Undefined Control sequence for \IF

\documentclass{article}
\usepackage{algorithm,algpseudocode}
\begin{document}
\begin{algorithm}
\caption{$Game PrvInd_{G,\phi}$}
\label{pseudoPSO}
\begin{algorithmic}[1]
\If{$f(\phi(f0) \neq\phi(f1)$}
\Return $\perp$ \EndIf
\If {$ev(f_0, x_0) \neq ev(f_1, x_1)$}
\Return $\perp$ \EndIf
\If{$\{x_0,x_1\} \nsubseteq \{0,1\}^{{f_0}.n}$}\Return $\prep$ \EndIf
$(F, e, d) \leftarrow Gb(1^k, f_b)$;
$X \leftarrow En(e, x_b)$
\Return (F,X, d)

\end{algorithmic}
\end{algorithm}
\end{document}


While writing algorithm in latex I am getting undefined control sequence for \If at line 12.

Also is it possible to use all 3 if without having end if?

## 1 Answer

You need amssymb for \nsubseteq:

\documentclass{article}

\usepackage{algorithm,algpseudocode}
\algtext*{EndIf}% Remove \EndIf
\usepackage{amsmath,amssymb}

\begin{document}

\begin{algorithm}
\caption{Game $\text{PrvInd}_{G,\phi}$}
\label{pseudoPSO}
\begin{algorithmic}[1]
\If{$f(\phi(f0) \neq \phi(f1))$} \Return $\perp$
\EndIf
\If {$\text{ev}(f_0, x_0) \neq \text{ev}(f_1, x_1)$} \Return $\perp$
\EndIf
\If{$\{x_0,x_1\} \nsubseteq \{0,1\}^{f_0 \cdot n}$} \Return $\perp$
\EndIf
\State $(F, e, d) \leftarrow \text{Gb}(1^k, f_b)$;
\State $X \leftarrow \text{En}(e, x_b)$;
\State \Return $(F, X, d)$;
\end{algorithmic}
\end{algorithm}

\end{document}