plot2 new line



Hi,

I make a plot using plot2d and gnuplot.
I woould like to make a title :

title_string :concat(" 'Apollonian Gasket defined by curvatures (",string
(r0*k0),", ",string(nk1),", ",string(nk1),", ",string(nk1)," )" );
my_preamble:sconcat("unset key; set size ratio 1; set title 
",title_string);
set_plot_option([gnuplot_preamble,my_preamble])$ 

plot2d (plot_list)$

How can I brake a title line to 2 lines ?
( puting /n sign into title_string does not work for me 

title_string :concat(" 'Apollonian Gasket /n defined by curvatures 
(",string(r0*k0),", ",string(nk1),", ",string(nk1),", ",string
(nk1)," )" ); /* this does not work */


Thx

Adam