
\begin{enumerate}
\item $\dfrac{1}{3}\in\intervFF{-1}{\dfrac{1}{2}}$ car $\dfrac{1}{3}\approx0,333\ldots$
\item $\dfrac{7}{5}\notin\intervFF{0}{1}$ car $\dfrac{7}{5}=1,4$.
\item $\dfrac{8}{9}\in\intervFF{0}{1}$ car $0<8<9$.
\item $-\dfrac{9}{7}\in\intervFF{-2}{-1}$ car $-\dfrac{9}{7}\approx-1,2857\ldots$
\item $\dfrac{9}{4}\in\intervFF{2}{3}$ car $\dfrac{9}{4}=2,25$.
\item $\dfrac{8}{5}\notin\intervOO{1,6}{1,7}$ car $\dfrac{8}{5}=1,6$ (attention aux crochets ouverts !)
\item $\dfrac{1}{\pi}\notin\intervFF{\pi}{\pi+1}$ car $0<\dfrac{1}{\pi}<1$ et $\pi>1$.
\item $\dfrac{15}{14}\notin\intervFF{1,06}{1,07}$ car $\dfrac{15}{14}\approx1,0714\ldots$
\item $-\dfrac{20}{21}\in\intervFF{-1}{-0,9}$ car $-\dfrac{20}{21}\approx-0,95\ldots$
\item $-\dfrac{78}{79}\in\intervOO{-0,99}{-0,98}$ car $-\dfrac{78}{79}\approx-0,987\ldots$
\end{enumerate}
