  We analize the role of GL_2, a quantum group constructed by Dipper-Donkin, as
a global symmetry for quantum chains, and show the way to construct all
possible Hamiltonians for four states quantum chains with GL_2 global symmetry.
In doing this, we search all inner actions of GL_2 on the Clifford algebra
C(1,3) and show them. We also introduce the corresponding operator algebras,
invariants and Hamiltonians, explicitly.
