vm.selected=[];

    vm.items=['Lunes','Martes','Miércoles','Jueves','Viernes','Sábado','Domingo'];

    vm.exists = function (item, list) {
        return list.indexOf(item) > -1;
    };

    vm.toggle = function (item, list) {
        var idx = list.indexOf(item);
        if (idx > -1) {
            list.splice(idx, 1);
        }
        else {
            list.push(item);
        }
    };

    vm.isIndeterminate = function() {
        return (vm.selected.length !== 0 &&
                vm.selected.length !== vm.items.length);
    };

    vm.isChecked = function() {
        return vm.selected.length === vm.items.length;
    };

    vm.toggleAll = function() {
        if (vm.selected.length === vm.items.length) {
            vm.selected = [];
        } else if (vm.selected.length === 0 || vm.selected.length > 0) {
            vm.selected = vm.items.slice(0);
        }
    };