anchor.diff:  
      The email is validated and the process does not stop until the user enters a valid email address."
     (prompt msg :default default
  -	  :required-p required-p
  -	  :validator (clavier:valid-email)
  -	  :if-invalid (or if-invalid
  -			  (lambda (&optional value)
  -			    (say "Invalid email" :color error-color)))
  -	  :color color
  -	  :error-color error-color))
  +	      :required-p required-p
  +	      :validator (or (and validator (clavier:&& (clavier:valid-email)
  +							(make-validator validator)))
  +			     (clavier:valid-email))
  +	      :if-invalid (or if-invalid
  +			      (lambda (&optional value)
  +				(say "Invalid email" :color error-color)))
  +	      :color color
  +	      :error-color error-color))
   
   (defun prompt-url (&optional msg &key default 
   				   (required-p t) 
  
positive.code: 
  (defparameter *prompt-color* nil "The default prompt color.")
  (defparameter *prompt-error-color* nil "The default error color")
  
  (defun remove-options (args &rest keys)
    (let ((args (copy-list args))
  
negative.code: 	  :error-color error-color))
  
  (defun prompt-email (&optional msg &key default 
  				     (required-p t)
  				     validator
  				     if-invalid
  				     (color *prompt-color*)
  				     (error-color *prompt-error-color*))
  