Theorem ringn0

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

	Ref	Expression
Assertion	ringn0	|- Ring =/= (/)

Proof

Step	Hyp	Ref	Expression
1		vex	|- z e. _V
2		eqid	|- { <. ( Base ` ndx ) , { z } >. , <. ( +g ` ndx ) , { <. <. z , z >. , z >. } >. , <. ( .r ` ndx ) , { <. <. z , z >. , z >. } >. } = { <. ( Base ` ndx ) , { z } >. , <. ( +g ` ndx ) , { <. <. z , z >. , z >. } >. , <. ( .r ` ndx ) , { <. <. z , z >. , z >. } >. }
3	2	ring1	|- ( z e. _V -> { <. ( Base ` ndx ) , { z } >. , <. ( +g ` ndx ) , { <. <. z , z >. , z >. } >. , <. ( .r ` ndx ) , { <. <. z , z >. , z >. } >. } e. Ring )
4		ne0i	|- ( { <. ( Base ` ndx ) , { z } >. , <. ( +g ` ndx ) , { <. <. z , z >. , z >. } >. , <. ( .r ` ndx ) , { <. <. z , z >. , z >. } >. } e. Ring -> Ring =/= (/) )
5	1 3 4	mp2b	|- Ring =/= (/)