added require to the teaching languages

svn: r6018

collects/lang/htdp-advanced.ss

@@ -9,6 +9,8 @@
 	   (lib "docprovide.ss" "syntax")
 	   "posn.ss")
 
+  (provide require)
+  
   ;; syntax:
   (provide (rename advanced-define define)
 	   (rename advanced-define-struct define-struct)

collects/lang/htdp-beginner-abbr.ss

@@ -5,6 +5,8 @@
 	   (lib "math.ss")
 	   (lib "docprovide.ss" "syntax"))
 
+  (provide require)
+  
   ;; Implements the forms:
   (require "private/teach.ss"
 	   "private/contract-forms.ss"

collects/lang/htdp-beginner.ss

@@ -7,6 +7,8 @@
   (require (lib "etc.ss")
 	   (lib "list.ss")
 	   (lib "docprovide.ss" "syntax"))
+
+  (provide require)
   
   ;; Implements the forms:
   (require "private/teach.ss"

collects/lang/htdp-intermediate-lambda.ss

@@ -5,7 +5,9 @@
 	   (lib "etc.ss")
 	   (lib "list.ss")
 	   (lib "docprovide.ss" "syntax"))
-
+  
+  (provide require)
+  
   ;; syntax:
   (provide (rename intermediate-define define)
 	   (rename intermediate-define-struct define-struct)

collects/lang/htdp-intermediate.ss

@@ -7,6 +7,8 @@
 	   (lib "list.ss")
 	   (lib "docprovide.ss" "syntax"))
 
+  (provide require)
+  
   ;; syntax:
   (provide (rename intermediate-define define)
 	   (rename intermediate-define-struct define-struct)