For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:qwert2003/openSUSE_Tumbleweed/home:qwert2003.repo
zypper refresh
zypper install yacas
For openSUSE Factory ARM run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:qwert2003/openSUSE_Factory_ARM/home:qwert2003.repo
zypper refresh
zypper install yacas
For 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:qwert2003/15.6/home:qwert2003.repo
zypper refresh
zypper install yacas
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:qwert2003/15.5/home:qwert2003.repo
zypper refresh
zypper install yacas
For 15.4 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:qwert2003/15.4/home:qwert2003.repo
zypper refresh
zypper install yacas