How to run 32-bit app in recent Ubuntu 64-bit

In short: exactly the same question as "How to run 32-bit app in Ubuntu 64-bit", but because its answer is no longer working.

Details:

$ bios/extlinux/extlinux
bash: bios/extlinux/extlinux: No such file or directory

$ file bios/extlinux/extlinux 
bios/extlinux/extlinux: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux.so.2, for GNU/Linux 2.6.32, BuildID[sha1]=6b439421a757a6f3a4218c726538be790a22ca13, stripped

$ uname -m
x86_64

$ lsb_release -a 
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 16.04 LTS
Release:        16.04
Codename:       xenial

I.e., under Ubuntu Xenial the previous working answer no longer working:

$ sudo dpkg --add-architecture i386

$ sudo apt-get install libc6:i386 libncurses5:i386 libstdc++6:i386
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Package libc6:i386 is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
However the following packages replace it:
  libdb1-compat initscripts tzdata

E: Package 'libc6:i386' has no installation candidate
E: Unable to locate package libncurses5:i386
E: Unable to locate package libstdc++6:i386
E: Couldn't find any package by regex 'libstdc++6'

Solution 1:

Found it myself,

apt-get install libc6-i386

Willing to accept anybody's answer as the answer.