Metamath Proof Explorer


Theorem 0wdom

Description: Any set weakly dominates the empty set. (Contributed by Stefan O'Rear, 11-Feb-2015)

Ref Expression
Assertion 0wdom ⊢ X ∈ V → ∅ ≼ * X

Proof

Step Hyp Ref Expression
1 eqid ⊢ ∅ = ∅
2 1 orci ⊢ ∅ = ∅ ∨ ∃ z z : X ⟶ onto ∅
3 brwdom ⊢ X ∈ V → ∅ ≼ * X ↔ ∅ = ∅ ∨ ∃ z z : X ⟶ onto ∅
4 2 3 mpbiri ⊢ X ∈ V → ∅ ≼ * X