\begin{frame}{LL$(k)$ Grammars}
  The class of LL$(1)$ grammars is often to restrictive in practice.
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  LL$(1)$ parsers looks at $1$ symbol to decide which rule to use.
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  \begin{goal}{}
    An \alert{LL$(k)$} parser \alert{looks $k$ symbols ahead} to choose the rule. 
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    The parser table is constructed with $k$ symbols look-ahead.
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    A grammar is LL$(k)$ if this table has in every cell $\le 1$ rule. 
  \end{goal}
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  LL$(k)$ is strictly contained in LL$(k+1)$.
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  \emph{Disadvantage}: size of the parser table grows exponential in $k$.
\end{frame}