diff --git a/ex-3_24-xx.scm b/ex-3_24-xx.scm
index 45dfccb..511527c 100644
--- a/ex-3_24-xx.scm
+++ b/ex-3_24-xx.scm
@@ -1,4 +1,107 @@
 (load "util.scm")
 
-(display "\nex-3.24\n")
+(display "example - tables\n")
+
+(define (make-table same-key?)
+  (define (assoc key records)
+    (cond ((null? records) false)
+          ((same-key? key (caar records)) (car records))
+          (else (assoc key (cdr records)))))
+  (let ((local-table (list '*table*)))
+    (define (lookup key-1 key-2)
+      (let ((subtable (assoc key-1 (cdr local-table))))
+        (if subtable
+            (let ((record (assoc key-2 (cdr subtable))))
+              (if record
+                  (cdr record)
+                  false))
+            false)))
+    (define (insert! key-1 key-2 value)
+      (let ((subtable (assoc key-1 (cdr local-table))))
+        (if subtable
+            (let ((record (assoc key-2 (cdr subtable))))
+              (if record
+                  (set-cdr! record value)
+                  (set-cdr! subtable
+                            (cons (cons key-2 value)
+                                  (cdr subtable)))))
+            (set-cdr! local-table
+                      (cons (list key-1
+                                  (cons key-2 value))
+                            (cdr local-table)))))
+      'ok)
+    (define (dispatch m)
+      (cond ((eq? m 'lookup-proc) lookup)
+            ((eq? m 'insert-proc!) insert!)
+            (else (error "Unknown operation -- TABLE" m))))
+    dispatch))
+
+(define operation-table (make-table equal?))
+(define get (operation-table 'lookup-proc))
+(define put (operation-table 'insert-proc!))
+
+(put 'a 'b 'c)
+(put 'd 'e 'f)
+(assert (get 'd 'e) 'f)
+(assert (get 'a 'b) 'c)
+
+(display "\nex-3.24 - same-key?\n")
+
+(define t (make-table (lambda (a b) (<= (abs (- a b)) 1))))
+(define get (t 'lookup-proc))
+(define put (t 'insert-proc!))
+
+(put 4 2 42)
+(assert (get 5 1) 42)
+(assert (get 6 0) #f)
+
+
+(display "\nex-3.25 - generalized tables\n")
+
+(define (make-table same-key?)
+  (define (assoc key records)
+    (display "assoc ") (display key) (display " ") (display records) (newline)
+    (cond ((null? records) false)
+          ((same-key? key (caar records)) (car records))
+          (else (assoc key (cdr records)))))
+  (let ((local-table (list '*table*)))
+    (define (lookup-generic . keys)
+      (display keys) (newline)
+      (lookup keys (cdr local-table)))
+    (define (lookup keys subtable)
+      (display "lookup ") (display keys) (display " ") (display subtable) (newline)
+      (cond
+        ((not subtable) #f)
+        ((null? keys) (cdr subtable))
+        (else (lookup (cdr keys) (assoc (car keys) subtable)))))
+    (define (insert! key-1 key-2 value)
+      (let ((subtable (assoc key-1 (cdr local-table))))
+        (if subtable
+            (let ((record (assoc key-2 (cdr subtable))))
+              (if record
+                  (set-cdr! record value)
+                  (set-cdr! subtable
+                            (cons (cons key-2 value)
+                                  (cdr subtable)))))
+            (set-cdr! local-table
+                      (cons (list key-1
+                                  (cons key-2 value))
+                            (cdr local-table)))))
+      'ok)
+    (define (dispatch m)
+      (cond ((eq? m 'lookup-proc) lookup-generic)
+            ((eq? m 'insert-proc!) insert!)
+            (else (error "Unknown operation -- TABLE" m))))
+    dispatch))
+
+(define operation-table (make-table equal?))
+(define get (operation-table 'lookup-proc))
+(define put (operation-table 'insert-proc!))
+(put 'a 'b 'c)
+(put 'd 'e 'f)
+(assert (get 'd 'e) 'f)
+;(assert (get 'a 'b) 'c)
+
+
+(display "\nex-3.26\n")