@freemo {1,4} and {2,3} are closely related. {2,3,4} existed alongside each other and {1} was at least somewhat common to hear about in the Golden Age of Islam. They could all be considered to be Abrahamic. With {1} it would be difficult to argue that point except for the beliefs and customs of {2,3,4} influencing {1} where it adopts or rejects them. [Just wait for the end.]

In the modern world, {1} is largely a product of {2,3,4} and they should be included in a larger set(foreshadowing). The cultures of all 4 are rich. They have nurtured science in different ways. The idea of a god being an alien isn't explicitly denounced. This would make an argument for {1} being in {2,3,4} as it's not a god but not necessarily as it would be a higher power.

So let's take the set T as {2,3,4}. The Powerset P(T) is {{0},{2},{3},{4},{2,3},{2,4},{3,4},{2,3,4}} and this is the set of all subsets of T. It's Abelian Group(Ignore the numbers) so it contains an identity and the sets are their own inverse when using symmetric difference. The number of subsets is 8 including the null set. Could {1} be considered like the null set? Look at the Elements of T and of P(T). What would a null set be if it's the identity element? So e / a = a and a / a = e. So why does {1} fit the description of the null set. It does essentially because I said so and typed this up for a point.

It's not possible to be proven with Mathematics but the patterns of the Powerset resemble the influence of religions on each other. Some are unchanged and others are combinations. Why the weird Mathematics? The Null Set and it being the identity. In P(T) there is one element that doesn't appear apart from itself. It essentially means that it has nothing in common.

The most interesting thing about {1,2,3,4} is that {1} can be viewed as the null set which it would fit the definition for. This also means the set of all subsets of {2,3,4} would include the null set which would be the identity element. So within the set of religions there would be a non religion sub set.