Wolfenstein suggested a rather convenient approximate parameterization of hte CKM matrix [9],
where there are four parameters, 
and 
, that have to be obtained from experiment. Of the four, 
and A are relatively well determined; less is know about 
and .
The parameter , which is the sine of the Cabibbo angle,
is determined
from strange particle decays ( 
) [10, 11], nuclear 
decay ( 
) [12], and the production
of charm in 
interactions ( 
) [13, 14] to be
The semileptonic width of the B meson, determined from its lifetime 
and semileptonic branching ratio 
, yields the best measurement of A [15],
The relative strength of 
and 
transition in semileptonic B decays [16] determines the ratio
In addition, there are three other constraints on and . The strength for 
mixing, 
, dominated by the t-quark exchange diagram and can be expressed in terms of 
as [17]
Here 
is the 
decay constant and 
is the so-called bag parameter--both have theoretical uncertainties. The observed CP violation in the 
mass matrix, 
, is proportional to [18],
where 
and 
are 
and 
, respectively, and expressions for the functions S and F are given in ref [18].
Limits on direct CP violation in 
S = 1 
decays ( 
) can be translated to limits on given by [19],
