Cardinality of sum types

sum_types_cardinality.kt

sealed class NotificationSetting
object Disabled : NotificationSettings()    // an object has one element -> cardinality = 1
data class Enabled(val pushEnabled: Boolean, val emailEnabled: Boolean) : NotificationSettings()

// cardinality = cardinality (Disabled)  + cardinality(Enabled)
// cardinality = 1 + (2 * 2)
// cardinality = 1 + 4 = 5

sealed class Location
object Unknown : Location()
data class Somewhere(val lat: Float, val lng: Float) : Location()

// cardinality = cardinality (Unknown)  + cardinality(Somewhere)
// cardinality = 1 + (∞ * ∞)
// cardinality = 1 + ∞ = ∞