Combination_Terms       StepBetaBinomial internal object
StepBeta                Stepwise model selection for Beta Regression
Step_glimML             Stepwise model selection for Beta-Binomial and
                        Negative Binomial Regressions from aod package
check_formula_terms     StepBeta and StepBetaBinomial internal object
dispersion_formula_terms
                        StepBeta internal object
keep_formula_terms      StepBeta internal object
remove_formula_interactions
                        StepBeta internal object
