anchor.diff:  	;; Calculate list of library-versions involved
   	(let ((library-versions-involved
   	       (calculate-library-versions-involved library-version)))
  -
  -	  ;; Validate the library versions list
  -                                        ;(validate-library-versions-list library-versions)
  -
  +	  
   	  (let ((library-versions (pbo-solve-library-versions library-version
   							      library-versions-involved)))
   	    ;; Remove the project library from the library versions list
  
positive.code:       ;; Calculate list of library-versions involved
        (let ((library-versions-involved
               (calculate-library-versions-involved library-version)))
  
          ;; Validate the library versions list
                                          ;(validate-library-versions-list library-versions)
  
          (let ((library-versions (pbo-solve-library-versions library-version
                                                              library-versions-involved)))
  
negative.code: 	(let ((library-versions-involved
  	       (calculate-library-versions-involved library-version)))
  
  	  (let ((library-versions (pbo-solve-library-versions library-version
  							      library-versions-involved)))
  	    ;; Remove the project library from the library versions list
  