Description: Membership of the empty set in an infinite Cartesian product. (Contributed by Steve Rodriguez, 29-Sep-2006)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | 0elixp | ⊢ ∅ ∈ X 𝑥 ∈ ∅ 𝐴 | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | 0ex | ⊢ ∅ ∈ V | |
| 2 | 1 | snid | ⊢ ∅ ∈ { ∅ } | 
| 3 | ixp0x | ⊢ X 𝑥 ∈ ∅ 𝐴 = { ∅ } | |
| 4 | 2 3 | eleqtrri | ⊢ ∅ ∈ X 𝑥 ∈ ∅ 𝐴 |