% sstipics.t13 -- generated from sstipics.mp
\fmfL(0.41513,-1.80826,rt){$y$}%
\fmfL(0.41513,21.80826,rb){$x_1$}%
\fmfL(14.58487,-1.80826,lt){$x_2$}%
\fmfL(14.58487,21.80826,lb){$x_3$}%
