coef.intReg             Extract (only informative) coefficients,
                        standard errors, and variance-covariance matrix
                        from 'intReg' model.
intReg                  Interval Regression
model.frame.intReg      Data used for estimating interval regression
                        model
model.matrix.intReg     Design Matrix of Interval Regression Models
nObs.intReg             Number of observations.
