(define-public (convert-to-ps . args) #t)
(define-public (convert-to-pdf . args) #t)
(define-public (convert-to-png . args) #t)
(define-public (convert-to-ps . args) #t)
(define-public (convert-to-pdf . args) #t)
(define-public (convert-to-png . args) #t)