The code in this library section is not supported by StatSci.

The functions in this section are described in chapter 11 of "The New S
Language" by Becker, Chambers and Wilks (1988).  They implement a model
for the evaluation of S expressions, and for some special S functions.

Eval(expr, frame)		#The model evaluator

		# Used by the model evaluator
Eval.init
New.frame
Program
Insert
Replace.assign
Replace.expr
Do.internal
Logical.value
Get
expd.assign

		# special functions
Switch
Missing
%&&%
%||%

		# functions in the model for subscripting
a.to.vec.index
array.indices
vec.index