Metamath Proof Explorer


Theorem ringn0

Description: Rings exist. (Contributed by AV, 29-Apr-2019)

Ref Expression
Assertion ringn0 ⊢ Ring ≠ ∅

Proof

Step Hyp Ref Expression
1 vex ⊢ z ∈ V
2 eqid ⊢ Base ndx z + ndx z z z ⋅ ndx z z z = Base ndx z + ndx z z z ⋅ ndx z z z
3 2 ring1 ⊢ z ∈ V → Base ndx z + ndx z z z ⋅ ndx z z z ∈ Ring
4 ne0i ⊢ Base ndx z + ndx z z z ⋅ ndx z z z ∈ Ring → Ring ≠ ∅
5 1 3 4 mp2b ⊢ Ring ≠ ∅