Metamath Proof Explorer


Theorem rng1nnzr

Description: The (smallest) structure representing a zero ring is not a nonzero ring. (Contributed by AV, 29-Apr-2019)

Ref Expression
Hypothesis rng1nnzr.m
|- M = { <. ( Base ` ndx ) , { Z } >. , <. ( +g ` ndx ) , { <. <. Z , Z >. , Z >. } >. , <. ( .r ` ndx ) , { <. <. Z , Z >. , Z >. } >. }
Assertion rng1nnzr
|- ( Z e. V -> M e/ NzRing )

Proof

Step Hyp Ref Expression
1 rng1nnzr.m
 |-  M = { <. ( Base ` ndx ) , { Z } >. , <. ( +g ` ndx ) , { <. <. Z , Z >. , Z >. } >. , <. ( .r ` ndx ) , { <. <. Z , Z >. , Z >. } >. }
2 snex
 |-  { Z } e. _V
3 1 rngbase
 |-  ( { Z } e. _V -> { Z } = ( Base ` M ) )
4 2 3 mp1i
 |-  ( Z e. V -> { Z } = ( Base ` M ) )
5 4 eqcomd
 |-  ( Z e. V -> ( Base ` M ) = { Z } )
6 5 fveq2d
 |-  ( Z e. V -> ( # ` ( Base ` M ) ) = ( # ` { Z } ) )
7 hashsng
 |-  ( Z e. V -> ( # ` { Z } ) = 1 )
8 6 7 eqtrd
 |-  ( Z e. V -> ( # ` ( Base ` M ) ) = 1 )
9 1 ring1
 |-  ( Z e. V -> M e. Ring )
10 0ringnnzr
 |-  ( M e. Ring -> ( ( # ` ( Base ` M ) ) = 1 <-> -. M e. NzRing ) )
11 9 10 syl
 |-  ( Z e. V -> ( ( # ` ( Base ` M ) ) = 1 <-> -. M e. NzRing ) )
12 8 11 mpbid
 |-  ( Z e. V -> -. M e. NzRing )
13 df-nel
 |-  ( M e/ NzRing <-> -. M e. NzRing )
14 12 13 sylibr
 |-  ( Z e. V -> M e/ NzRing )