Metamath Proof Explorer


Theorem abln0

Description: Abelian groups (and therefore also groups and monoids) exist. (Contributed by AV, 29-Apr-2019)

Ref Expression
Assertion abln0 ⊢ Abel ≠ ∅

Proof

Step Hyp Ref Expression
1 vex ⊢ i ∈ V
2 eqid ⊢ Base ndx i + ndx i i i = Base ndx i + ndx i i i
3 2 abl1 ⊢ i ∈ V → Base ndx i + ndx i i i ∈ Abel
4 ne0i ⊢ Base ndx i + ndx i i i ∈ Abel → Abel ≠ ∅
5 1 3 4 mp2b ⊢ Abel ≠ ∅