***************
*** 117,125 ****
        (define/public (undo-all)
          (send acl2-process reset-acl2))
  
        (define/public (certify-book filename)
          (send acl2-process reset-acl2)
-         (send acl2-process send-to-repl `(certify-book ,filename 1)))
        
        ;; definitions:text<%> -> void
        (define/public (undo-last dt)
--- 117,136 ----
        (define/public (undo-all)
          (send acl2-process reset-acl2))
  
+       (define (acl2-filename str)
+         (let* ([sys-type (system-path-convention-type)])
+           (case sys-type
+             [(unix) str]
+             [(windows) (regexp-replace* "\\\\" str "/")]
+             [else (error 'acl2-filename
+                          "cannot build path for unknown system type ~s"
+                          sys-type)])))
+ 
        (define/public (certify-book filename)
          (send acl2-process reset-acl2)
+         (send acl2-process
+               send-to-repl
+               `(certify-book ,(acl2-filename filename) 1)))
        
        ;; definitions:text<%> -> void
        (define/public (undo-last dt)