LaTeX 2.09 :

\documentstyle[twoside,epsfig]{article} % Select style. \begin{document} % Begin document. . . % Text of document. . \end{document} % End document.

LaTeX 2e :

\documentclass[twoside]{article} % Select style. \usepackage{epsfig} \begin{document} % Begin document. . . % Text of document. . \end{document} % End document.

And...

• ${\mathcal P}$ vs $\mathcal{P}$. . .