R_NaN
R_NaInt 
R_NaReal
R_NegInf
R_PosInf 
m_one
m_zero
CharacterMode
UserBreak
R_GlobalEnv
R_NilValue
R_UnboundValue
R_MissingArg
R_Bracket2Symbol
R_BracketSymbol
R_ClassSymbol
R_DimNamesSymbol
R_DimSymbol
R_DollarSymbol
R_DotsSymbol
R_DropSymbol
R_LevelsSymbol
R_ModeSymbol
R_NamesSymbol
R_NaRmSymbol
R_RowNamesSymbol
R_SeedsSymbol
R_TspSymbol
R_LastvalueSymbol
R_CommentSymbol
R_NaString
R_BlankString
R_PreciousList
R_Visible
R_EvalDepth