angularjs select element if false OR null/undefined

I have the code below but I would like "No" to be select if s.x.user_chose_is_formula is false, null, or undefined (all in a single option). How do I do that?

            md-input-container.values-type-select
              label Values Type:
              md-select(ng-model="s.x.user_chose_is_formula")
                md-option(ng-value="true") Yes
                md-option(ng-value="false") No