Added comments

polynomials/poly.rkt

@@ -3,6 +3,7 @@
 (module common racket/base
   (provide curly?)
   (define (curly? stx)
+    ; Was the form in stx written with curly parentheses?    
     (let ([p (syntax-property stx 'paren-shape)])
       (and p 
            (or (eqv? p #\{)

statistics/chi-squared-test.rkt

@@ -1,4 +1,9 @@
 #lang racket
+;;;
+;;; This module implements Chi-squared tests for goodness of fit and
+;;; independence of categories.
+;;;
+
 (require racket/flonum
          (planet williams/science:4:5/science)
          (only-in (planet williams/science/unsafe-ops-utils)