The Pauli matrices satisfy the above relation. It turns out that there are infinitely many more examples of sets of matrices that satisfy these relations, where each set comprises formula_102 matrices with formula_103, and where none of these can be thought to 'decompose' into two or more examples of lower dimension. They are called different irreducible representations of the formula_46 algebra. The most fundamental representation being the Pauli matrices. The holonomy is labelled by a half integer formula_105 according to the irreducible representation used.