What does the symbol for pi with a lower perpendicular mean?

principal components [xkcd repost]

\STATE [algorithmic package]

I fought with my L^αT_εX compiler this morning as it did not want to deal with my code:

 \begin{algorithmic}[1]
 \STATE N=1000
 \STATE $\hat\pi=0$
 \FOR {I=1,N}
 \STATE X=RDN(1), Y=RDN(1)
 \IF {$\text{X}^2+\text{Y}^2<1$}
 $\hat\pi$ = $\hat\pi +1$
 \ENDIF
 \ENDFOR
 \RETURN 4*$\hat\pi/$N
 \end{algorithmic}
 

looking on forums for incompatibilities between beamer and algorithmic, and adding all kinds of packages, to no avail. Until I realised one \STATE was missing:

 \begin{algorithmic}[1]
 \STATE N=1000
 \STATE $\hat\pi=0$
 \FOR {I=1,N}
 \STATE X=RDN(1), Y=RDN(1)
 \IF {$\text{X}^2+\text{Y}^2<1$}
 \STATE $\hat\pi$ = $\hat\pi +1$
 \ENDIF
 \ENDFOR
 \RETURN 4*$\hat\pi/$N
 \end{algorithmic}
 

(This is connected with my AMSI public lecture on simulation, obviously!)