utils: Remove type annotations.

I am very early in my project, and I have already spent literal days
trying to make the types fit together.

I'm trying contracts next.

bn.rkt

@@ -1,4 +1,4 @@
-#lang typed/racket
+#lang racket
 
 ;;; dds/bn
 
@@ -10,8 +10,6 @@
 (require "utils.rkt")
 
 (provide
- ;; Types
- Variable State UpdateFunc Network
  ;; Functions
  update make-state make-bn-funcs update-func-form->update-func
  bn-form->bn make-bn-forms

utils-tests.rkt

@@ -1,8 +1,8 @@
-#lang typed/racket
+#lang racket
 
 ;;; Tests for dds/utils.
 
-(require typed/rackunit "utils.rkt")
+(require rackunit "utils.rkt")
 
 (test-case "HashTable Injection"
   (test-case "auto-hash-ref/explicit"

utils.rkt

@@ -1,4 +1,4 @@
-#lang typed/racket
+#lang racket
 
 ;;; dds/utils
 
@@ -96,16 +96,14 @@
 ;;;         [z 1])
 ;;;     (eval-with ht '(+ b z a 1)))
 ;;;
-(: eval-with (-> (HashTable Symbol Any) Any AnyValues))
 (define (eval-with ht expr)
-  (parameterize ([current-namespace (current-namespace)])
+  (parameterize ([current-namespace (make-base-namespace)])
     (hash-for-each ht (lambda (x val)
                         (namespace-set-variable-value! x val)))
     (eval expr)))
 
 ;;; Same as eval-with, but returns only the first value produced by
 ;;; the evaluated expression.
-(: eval-with1 (-> (HashTable Symbol Any) Any Any))
 (define (eval-with1 ht expr)
   (let ([vals (call-with-values (λ () (eval-with ht expr))
                                 (λ vals vals))])
@@ -118,13 +116,10 @@
 
 ;;; Produces a list of symbols appearing in the quoted expression
 ;;; passed in the first argument.
-(: extract-symbols (-> Any (Listof Symbol)))
 (define (extract-symbols form)
   (cond
     [(symbol? form)
-     (list (cast form Symbol))]
+     (list form)]
     [(list? form)
-     (cast (flatten (for/list : (Listof (Listof Symbol))
-                        ([x (cast form (Listof Any))])
-                      (extract-symbols x))) (Listof Symbol))]
+     (flatten (for/list ([x form]) (extract-symbols x)))]
     [else '()]))