/usr/lib/x86_64-linux-gnu/libslp.so.1 is in libslp1 1.2.1-11.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libslp.so.1.0.1
/usr/lib/x86_64-linux-gnu/libslp.so.1.0.1