gens {
x y z t u 
}
rels {
x*x y*y z*z t*t u*u
x*y*x*y*x*y y*z*y*z*y*z z*t*z*t*z*t z*u*z*u*z*u
x*z*x*z x*t*x*t x*u*x*u
y*t*y*t y*u*y*u t*u*t*u
}
