anchor.diff:    #     end
     #   }
     #
  -  #   nav_sections
  +  #   addl_sections
     # }
   -%>
   <!DOCTYPE html>
  
positive.code: <%-
    @nav_sections = []
    @subnav_sections = []
    
    if is_logged_in_user?
      if user_has_permission?(:manage_cms)
  
negative.code:     @nav_sections += ImagineCmsAdditionalNavSections.is_a?(Proc) ? ImagineCmsAdditionalNavSections.call(self) : ImagineCmsAdditionalNavSections
    end
    
    if defined?(ImagineCmsAdditionalSubnavSections)
      @subnav_sections += ImagineCmsAdditionalSubnavSections.is_a?(Proc) ? ImagineCmsAdditionalSubnavSections.call(self) : ImagineCmsAdditionalSubnavSections
    end
    
    #
    # how to use a Proc to add nav sections:
    #
    # ImagineCmsAdditionalNavSections = Proc.new { |context|
    #   addl_sections = []
    #
    #   context.instance_eval {
    #     if is_logged_in_user?
  