/usr/share/xfig/Libraries/DSP/ is in xfig-libs 1:3.2.6a-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/xfig/Libraries/DSP/1toN.fig
/usr/share/xfig/Libraries/DSP/1toNtime.fig
/usr/share/xfig/Libraries/DSP/FFT.fig
/usr/share/xfig/Libraries/DSP/IFFT.fig
/usr/share/xfig/Libraries/DSP/Nto1.fig
/usr/share/xfig/Libraries/DSP/Nto1time.fig
/usr/share/xfig/Libraries/DSP/README
/usr/share/xfig/Libraries/DSP/adder.fig
/usr/share/xfig/Libraries/DSP/biquad.fig
/usr/share/xfig/Libraries/DSP/comparator.fig
/usr/share/xfig/Libraries/DSP/delay.fig
/usr/share/xfig/Libraries/DSP/demux.fig
/usr/share/xfig/Libraries/DSP/directform.fig
/usr/share/xfig/Libraries/DSP/downsample.fig
/usr/share/xfig/Libraries/DSP/filterbank.fig
/usr/share/xfig/Libraries/DSP/fraction_format.fig
/usr/share/xfig/Libraries/DSP/integrator.fig
/usr/share/xfig/Libraries/DSP/lpf.fig
/usr/share/xfig/Libraries/DSP/model.fig
/usr/share/xfig/Libraries/DSP/mul_composition.fig
/usr/share/xfig/Libraries/DSP/mult.fig
/usr/share/xfig/Libraries/DSP/mult_modul.fig
/usr/share/xfig/Libraries/DSP/mux.fig
/usr/share/xfig/Libraries/DSP/phasecomp.fig
/usr/share/xfig/Libraries/DSP/register.fig
/usr/share/xfig/Libraries/DSP/sum_composition.fig
/usr/share/xfig/Libraries/DSP/transfer.fig
/usr/share/xfig/Libraries/DSP/upsample.fig