\begin{definition}[Definition:Chess/Pawn]
A '''pawn''' File:Chess plt45.svg may move in the following modes.
$(1): \quad$ It may move one square towards the opposing player, {{iff}} that square is empty.
$(2): \quad$ If it has not yet been moved, and {{iff}} both of the squares is empty, it may move $2$ squares forward instead of $1$.
Some authorities do not classify the pawn as a piece.
\end{definition}