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