/*REXX program demonstrates  interactive programming  by using a  function [F].         */
say f('Rosetta',  "Code",  ':')
say f('The definition of a trivial program is ',  " one that has no bugs.",  '───')
exit                                             /*stick a fork in it,  we're all done. */
/*──────────────────────────────────────────────────────────────────────────────────────*/
f:  return arg(1) || copies(arg(3),2) || arg(2)  /*return the required string to invoker*/