From 0f78892a0be666c709108ad511de23c761b17365 Mon Sep 17 00:00:00 2001
From: Matthias Felleisen <matthias@ccs.neu.edu>
Date: Sun, 21 Sep 2014 12:26:47 -0500
Subject: [PATCH] closes PR 14744 , Rackety

---
 pkgs/htdp-pkgs/htdp-lib/lang/prim.rkt          | 16 +++++++---------
 .../htdp-lib/lang/private/beginner-funs.rkt    | 18 +++++++++++++++---
 2 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/pkgs/htdp-pkgs/htdp-lib/lang/prim.rkt b/pkgs/htdp-pkgs/htdp-lib/lang/prim.rkt
index 977300369d..2058902cf0 100644
--- a/pkgs/htdp-pkgs/htdp-lib/lang/prim.rkt
+++ b/pkgs/htdp-pkgs/htdp-lib/lang/prim.rkt
@@ -3,15 +3,15 @@
 ;; define a primitive operator that consumes a procedure.
 ;; See manual for more information.
 
-(module prim mzscheme
-  (require lang/error
-           (rename lang/htdp-beginner beginner-app #%app))
+#lang mzscheme
+(require lang/error
+  (rename lang/htdp-beginner beginner-app #%app))
   
-  (require-for-syntax (prefix fo: "private/firstorder.rkt")
+(require-for-syntax (prefix fo: "private/firstorder.rkt")
                       stepper/private/syntax-property)
   
-  (provide define-primitive
-	   define-higher-order-primitive
+(provide define-primitive
+         define-higher-order-primitive
 	   provide-primitive
 	   provide-higher-order-primitive
 	   provide-primitives
@@ -167,6 +167,4 @@
        (with-syntax ([ex-name ((make-syntax-introducer) #'name)])
 	 #'(begin
 	     (define-higher-order-primitive ex-name name (arg ...))
-	     (provide ex-name)))])))
-
-
+	     (provide ex-name)))]))
diff --git a/pkgs/htdp-pkgs/htdp-lib/lang/private/beginner-funs.rkt b/pkgs/htdp-pkgs/htdp-lib/lang/private/beginner-funs.rkt
index e1135249ae..c45058966f 100644
--- a/pkgs/htdp-pkgs/htdp-lib/lang/private/beginner-funs.rkt
+++ b/pkgs/htdp-pkgs/htdp-lib/lang/private/beginner-funs.rkt
@@ -276,9 +276,21 @@
                                          @interaction[#:eval (bsl) (even? 2)]
                                          }
   @defproc[(rational? [x any/c]) boolean?]{
-                                           Determines whether some value is a rational number. 
-                                           @interaction[#:eval (bsl) (rational? 1-2i)]
-                                           }
+   Determines whether some value is a rational number. 
+   @interaction[#:eval (bsl) 
+     (rational? 1)
+     (rational? -2.349)
+     (rational? #i1.23456789)
+     (rational? (sqrt -1))
+     (rational? pi)
+     (rational? e)
+     (rational? 1-2i)]
+  As the interactions show, the teaching languages considers many more
+  numbers as rationals than expected. In particular, @racket[pi] is a
+  rational number because it is only a finite approximation to the
+  mathematical π. Think of @racket[rational?] as a suggestion to think of
+  these numbers as fractions.
+  }
   @defproc[(inexact? [x number]) boolean?]{
                                            Determines whether some number is inexact.
                                            @interaction[#:eval (bsl) (inexact? 1-2i)]