Abelianization of first class constraints

We show that a given set of first class constraints becomes Abelian if one maps each constraint to the surface of other constraints. There is no assumption that first class constraints satisfy a closed algebra. The explicit form of the projection map is obtained at least for irreducible first class constraints. Using this map we give a method to obtain gauge fixing conditions such that the set of Abelian first class constraints and gauge fixing conditions satisfy the symplectic algebra.