+ ("pdf"
+ (viewer . pdf-view-mode)
+ (type . "application/pdf")
+ (test . (and (fboundp 'pdf-view-mode)
+ (eq window-system 'x))))
+ ("pdf"
+ (viewer . doc-view-mode)
+ (type . "application/pdf")
+ (test . (and (fboundp 'doc-view-mode)
+ (eq window-system 'x))))