  Model building based on abelian quiver gauge theories gives models which
resemble trinification, originally proposed with yottavolt unification.
However, unification occurs in the teravolt range so proton decay must be
completely excluded in the scalar sector. It is straightforward to accomplish
this by a discrete symmetry which is a generalized baryon number B. Unlike in
trinification, this is possible because quarks and leptons acquire masses from
relevant operators which appear in four-dimensional conformal symmetry
breaking.
