.K f1,f2,f3,f4,f5
.bra {
.ket }
;;    PR        --  Prints specified files; runs in
;;                  the background.

run mat >PRT: JOIN nolines TAG ^| {f1} {f2} {f3} {f4} {f5}
;                   ^^^ needed to suppress newline in tag

;; this is a simple (and hopefully obvious) application of the JOIN mode.
;; Depending on how you are looking at this script, you may have gotten
;; lost because of the form-feed character in the TAG argument.  Use an
;; editor that handles control characters to see it properly.