I am not sure if this question would belong to mathematics or more suitable for mathematics stackexchange. It comes from

https://jutho.github.io/TensorKit.jl/stable/man/tutorial/#Symmetries

```
julia> V1 = ℤ₂Space(0=>3,1=>2)
Rep[ℤ₂](0=>3, 1=>2)
julia> dim(V1)
5
```

I think Z2 is cyclic group, Cyclic group:Z2 - Groupprops, but why the dimension is 5? In some representation?