\begin{tabular}{llll} 
base & boot & class & cluster\\ 
datasets & foreign & graphics & grDevices\\ 
grid & KernSmooth & lattice & MASS\\ 
methods & mgcv & nlme & nnet\\ 
rpart & spatial & splines & stats\\ 
stats4 & survival & tcltk & tools\\ 
utils  &   &   &   \\ 
\end{tabular}
