--- /dev/null
+* form
+ * "(function element0 ...)"
+* building blocks of racket semantics
+** booleans
+ * "(zero? 1)" "(zero? (sub1 1))"
+** symbols
+ * a-z+-/*=<>?!_^
+ * (symbol=? 'foo 'FoO) true or false?
+** numbers
+ * "(expt 53 53)" "(= (/ 4 6) 2/3 (/ 2 3))" "(= (/ 4.0 6) 0.6666666666666666)"
+ * numbers like 4.0 are floating point numbers
+ * irrational numbers
+** strings
+ * "tutti frutti"
+ * (= (string-append "tutti" "frutti") "tuttifrutti")
+ * (= (string-append "tutti" " " "frutti") "tutti frutti")
+ * substring, string-ref, string=?
+** lists
+ * super duper important in racket
+*** cons cells
+ * (= (list 1 2) (cons 2 (cons 3 empty)))
+ * same as linked lists in other languages
+**** functions for cons cells
+ * (= (cons 1 2) '(1 . 2))
+ * (define cell (cons 'a 'b)) (= (car cell) 'a) (= (cdr cell) 'b)
+*** lists and list functions
+ * (= '() empty (list))
+**** cons function
+ * (= (cons 'chicken empty) '(chicken))
+ * empty is used to terminate lists in racket, so '(chicken) has
+ an implicit empty
+ * what do you get when you add a chicken to an empty list? a list with
+ a chicken in it
+ * (= (cons 'pork '(beef chicken)) '(pork beef chicken))
+ * (= (cons 'beef (cons 'chicken '())) '(beef chicken))
+ * (= (cons 'pork (cons 'beef (cons 'chicken '())))
+ '(pork beef chicken))
+**** list function
+ * (= (list 'pork 'beef 'chicken) '(pork beef chicken))
+**** first and rest functions
+ * (= (first (cons 'pork (cons 'beef (cons 'chicken empty)))) 'pork)
+ * (= (rest (list 'pork 'beef 'chicken)) '(beef chicken))
+ * (= (first (rest ('pork beef chicken))) 'beef)
+ * how do you get the third item?
+ * what happens when you try to get the fourth item?
+**** nested lists
+ * (= (list 'cat (list 'duck 'bat) 'ant) '(cat (duck bat) ant))
+ * all lists are made of cons cells
+ * (= (first '((peas carrots tomatoes) (pork beef chicken)))
+ (peas carrots tomatoes))
+ * (= (rest '(peas carrots tomatoes)) '(carrots tomatoes))
+ * (= (rest (first '((peas carrots tomatoes) (pork beef chicken))))
+ '(carrots tomatoes))
+ * second third ... tenth built-in