anchor.diff:       (not (qbf-eval a env)))
       ((list '=> a b)
        (qbf-eval `(-or ,b (-and (-not ,b) (-not ,a))) env))
  -    ((list 'forall a b)
  +    ((list '-forall a b)
        (flet ((try-with (bool) (qbf-eval b (extend env a bool))))
          (and (try-with '-true) (try-with '-false))))
       ((list '-var x)
  
positive.code: (defpackage :dsl-gen (:use :cl :optima))
  (in-package :dsl-gen)
  
  
negative.code:      `(not (qbf-evalm ,a ,env)))
      ((list '=> a b)
       `(qbf-evalm (-or ,b (-and (-not ,b) (-not ,a))) ,env))
      ((list '-forall a b)
       `(flet ((try-with (bool) (qbf-evalm ,b (extend env ,a bool))))
  	(and (try-with '-true) (try-with '-false))))
      ((list '-var x)
  