Write your own R function called $*$IsARCS$*,$ whose input is a vector storing the AR coefficient $$(\backslash$phi$\_1,\backslash$ldots$,\backslash$phi$\_$p$)$$ in the AR operator $$\backslash$phi$($B$)=1-\backslash$phi$\_1$ B$-\backslash$ldots$-\backslash$phi$\_$p B$^$p$$,$ and returns a logical value: TRUE means the corresponding AR model is causal stationary, FALSE means not.

Compare the output of your function with the stationarity checking result from $*$arima$.$sim$*.$