======Portable use of graphics characters======

Graphics characters are stored in an "alternate character set", which you
can turn on and off with the ALTCHARSET character (control-E).  When you are
in alternate character set mode, some of the characters are substituted with
other ("alternate") characters.

The $getcap(TERM acs_chars 0 0) function call will return to you all of the
characters that are substituted in the alternate character set.  This value
is a string that contains pairs of characters.  

The first character is a well-defined "vt100" alternate character name.

The second character is what character your emulator uses to support that
well-defined "vt100" alternate character.

Any characters that are not supported by your emulator are not shown in 
this list; you can't assume all characters will be supported -- some 
emulators may not support //any//.

======Example======
  @ foo = getcap(TERM acs_chars 0 0);
  fec ($foo) vt me {
	switch ($vt) {
		(w) { @tee_down = me }
		(u) { @tee_left = me }
		(t) { @tee_right = me }
		(v) { @tee_up = me }
		(l) { @ul_corner = me }
		(k) { @ur_corner = me }
		(m) { @ll_corner = me }
		(j) { @lr_corner = me }
		(x) { @vline = me }
		(q) { @hline = me }
	}
  }

  alias box (message) {
	echo $ul_corner$repeat(65 $hline)$ur_corner
	echo $vline$[65]center(65 $message)$vline
	echo $ll_corner$repeat(65 $hline)$lr_corner
  }

  box hi there!
  box w00t!