Notes from 10/09/02

- algol's way of doing copy rule
	- takes a copy of body, and inserts it for the function call
	- in that copy, substitutes copies of the value of argument for x
	- have to be careful - issues come up with simple-minded applications of this

- original lisp discussion
	- S-expressions
	- S stood for symbolic
	- also had M-expressions = meta expressions, not actually part of lisp
		- eval[(S-expression);...]

- atomic symbols
	- term from lisp
	- integers, rationals (scheme), reals (sort of), strings, symbols (been using these for variables), and the empty list ()
- atomic symbols don't get broken down furthur
- S-expression rules:
	- every atomic symbol is an S-expression
	- when a and b are both S-expressions, so is (a . b)
	- nothing else is an S-expression
- lists are shorthand
	- (a b c) = (a . (b . (c . ())))
	- tree structure
	- last thing is the empty list
	- also hangs off to the left to remove special cases

- list procedures
	- cons
		- constructs a pair
		- used to make lists, ie (cons a '(b c)) is the list (a b c)
	- car
		- first part of argument
		- ie the first element in a list
	- cdr
		- right part of an argument
		- ie the 'rest' of a list, everything but the first