diff --git a/beautiful-racket-demo/basic-demo-2/expr.rkt b/beautiful-racket-demo/basic-demo-2/expr.rkt
index d735549..ecef2a7 100644
--- a/beautiful-racket-demo/basic-demo-2/expr.rkt
+++ b/beautiful-racket-demo/basic-demo-2/expr.rkt
@@ -21,9 +21,4 @@
 
 (define-macro-cases b-expt
   [(_ VAL) #'VAL]
-  [(_ LEFT "^" RIGHT) #'(expt LEFT RIGHT)])
-
-(define (b-not expr) (if (zero? expr) 1 0))
-
-(define-macro (b-def ID VAR EXPR)
-  #'(set! ID (λ (VAR) EXPR)))
+  [(_ LEFT "^" RIGHT) #'(expt LEFT RIGHT)])
\ No newline at end of file