anchor.diff:  	(assert-equal "hello-world" (task-value 'execution-task-2))
   	(assert-equal "laughing-at-nothing" (task-value 'execution-task-3))))))
   
  ++
  +;;;; Execution parameters
   
   (define-task task-complete-p-t1 ()
     ())
  
positive.code:   (defmacro with-temporary-directory ((var) &body body)
      `(do-with-temporary-directory #'(lambda (,var)
  				      ,@body))))
  
  (define-test compute-chains
    (let ((chains (compute-chains (generate 'execution-design))))
  
negative.code: 
  	(perform area chain :iterations 0)
  	(assert-equal 0 (task-value 'task-complete-p-t2 chain area))))))
  
  