Metamath Proof Explorer
Description: The empty set is not a limit ordinal. (Contributed by NM, 24-Mar-1995)
(Proof shortened by Andrew Salmon, 25-Jul-2011)
|
|
Ref |
Expression |
|
Assertion |
nlim0 |
⊢ ¬ Lim ∅ |
Proof
Step |
Hyp |
Ref |
Expression |
1 |
|
noel |
⊢ ¬ ∅ ∈ ∅ |
2 |
|
simp2 |
⊢ ( ( Ord ∅ ∧ ∅ ∈ ∅ ∧ ∅ = ∪ ∅ ) → ∅ ∈ ∅ ) |
3 |
1 2
|
mto |
⊢ ¬ ( Ord ∅ ∧ ∅ ∈ ∅ ∧ ∅ = ∪ ∅ ) |
4 |
|
dflim2 |
⊢ ( Lim ∅ ↔ ( Ord ∅ ∧ ∅ ∈ ∅ ∧ ∅ = ∪ ∅ ) ) |
5 |
3 4
|
mtbir |
⊢ ¬ Lim ∅ |