Just (load 'ch1.scm') instead - laziness wins...
Exercise 1.29: introducing higher order functions (i.e., passing functions as arguments)
moved test code into its own procedure
Exercise 1.30: iterative summation
Exercise 1.31 - (product), by analogy with (sum), straight out of CS 1
disabled test suite invocation JUST in case you're reusing this file...
Exercise 1.32: refactoring (sum) and (product) into the more general (accumulate)
Exercise 1.33 (accumulate-filter), the uber-generalization
brief comment on how troublesome it is to write test code here...