post_install() {

    if ! getent group matemat >/dev/null; then
        groupadd --system matemat
    fi

    if ! getent passwd matemat >/dev/null; then
        useradd --system --create-home --gid matemat --home-dir /var/lib/matemat --shell /usr/bin/nologin matemat
    fi

    chown matemat:matemat -R /var/lib/matemat
    find /var/lib/matemat -type d -exec chmod 0750 {} \;
    find /var/lib/matemat -type f -exec chmod 0640 {} \;

    systemctl daemon-reload

}

pre_remove() {

    systemctl stop matemat.service
    userdel matemat

}

post_remove() {

    systemctl daemon-reload

}