C:/fndtn/Active/projects/CHAPTER6/Vprior2i.vhd -1 0:W:#0 Warning: The entity 'Vprior2' is out of date with respect to its
  source file 'C:/fndtn/Active/projects/CHAPTER6/Vprior2i.vhd'.  (LBR-3) 
C:\FNDTN\ACTIVE\PROJECTS\CHAPTER6\Vprior2.vhd -1 0:E:#0 Error: The architecture 'Vprior2(Vprior2_arch)' depends on the entity 'Vprior2'
  which has been analyzed more recently.
  Please re-analyze the source file for 'Vprior2(Vprior2_arch)' and try again.  (LBR-28) 

