$\setdef{1, 2}$ and $\setdef{1, 2}$
Terms
| Term | This example | Why |
|---|---|---|
| subset | ✓ | $\setdef{1, 2}$ is a subset of itself, as is every set. |
| proper subset | ✗ | $\setdef{1, 2}$ is not a proper subset of itself, because a proper subset must leave out some element. |
| element of | ✗ | $\setdef{1, 2}$ is not an element of itself, because its elements are $1$ and $2$. |