This operator pushes a second copy of the topmost object on the operand stack.
This command prints a copy of the entire stack, starting from the top and working to the bottom.
This command removes the topmost object from the stack and prints it.
David Maxwell,
who is still writing this, would like to
hear your comments and suggestions.
And remember, parts of this manual are based on
P.J. Weingartner's work:
A First Guide to PostScript.