Homogeneous and heterogeneous mixtures settle, or separate. As a homogeneous mixture, a solution has one phase (liquid) although the solute and solvent can vary: for example, salt water. Air can be more specifically described as a gaseous solution (oxygen and other gases dissolved in the major component, nitrogen). Since interactions between molecules play almost no role, dilute gases form rather trivial solutions. In part of the literature, they are not even classified as solutions. In gas intermolecular space is greatest and intermolecular force of attraction is least. In chemistry, a mixture is a substance containing two or more elements or compounds that are not
Phase-type distribution (the non-homogeneous case). The mixture of two Erlang distribution with parameter "E"(3,β), "E"(3,β) and (α,α) (such that α + α = 1 and for each "i", α ≥ 0) can be represented as a phase type distribution with and The Coxian distribution is a generalisation of the hypoexponential distribution. Instead of only being able to enter the absorbing state from state "k" it can be reached from any phase. The phase-type representation is given by, and where 0 < "p"...,"p" ≤ 1. In the case where all "p" = 1 we have the hypoexponential distribution. The Coxian distribution is extremely