the final mle estimates are :

                 coefficient     standard-error    t-ratio

  beta 0         0.98715305E+01  0.27194258E+00  0.36300055E+02
  beta 1         0.36795712E+00  0.17625902E-01  0.20875931E+02
  beta 2         0.51728719E+00  0.19966751E-01  0.25907429E+02
  sigma-squared  0.88939551E+00  0.14275452E+00  0.62302444E+01
  gamma          0.94956534E+00  0.90402880E-02  0.10503707E+03
   mu is restricted to be zero
  eta            0.11997870E+00  0.57515357E-02  0.20860289E+02


log likelihood function =  -0.29149749E+03


LR test of the one-sided error =   0.17594605E+04
with number of restrictions = 2
[note that this statistic has a mixed chi-square distribution]

不懂后面的LR···，以及这个混合卡方分布，如何对假设做出判断，原理是什么？请懂的朋友不吝赐教！