Binary package “libsfstdc++6” in ubuntu focal
GNU Standard C++ Library v3 (soft float ABI)
This package contains an additional runtime library for C++ programs
built with the GNU compiler.
.
libstdc++-v3 is a complete rewrite from the previous libstdc++-v2, which
was included up to g++-2.95. The first version of libstdc++-v3 appeared
in g++-3.0.