Step |
Hyp |
Ref |
Expression |
1 |
|
nzrring |
⊢ ( 𝑅 ∈ NzRing → 𝑅 ∈ Ring ) |
2 |
|
eqid |
⊢ ( Unit ‘ 𝑅 ) = ( Unit ‘ 𝑅 ) |
3 |
|
eqid |
⊢ ( 1r ‘ 𝑅 ) = ( 1r ‘ 𝑅 ) |
4 |
2 3
|
1unit |
⊢ ( 𝑅 ∈ Ring → ( 1r ‘ 𝑅 ) ∈ ( Unit ‘ 𝑅 ) ) |
5 |
|
eqid |
⊢ ( invg ‘ 𝑅 ) = ( invg ‘ 𝑅 ) |
6 |
2 5
|
unitnegcl |
⊢ ( ( 𝑅 ∈ Ring ∧ ( 1r ‘ 𝑅 ) ∈ ( Unit ‘ 𝑅 ) ) → ( ( invg ‘ 𝑅 ) ‘ ( 1r ‘ 𝑅 ) ) ∈ ( Unit ‘ 𝑅 ) ) |
7 |
1 4 6
|
syl2anc2 |
⊢ ( 𝑅 ∈ NzRing → ( ( invg ‘ 𝑅 ) ‘ ( 1r ‘ 𝑅 ) ) ∈ ( Unit ‘ 𝑅 ) ) |
8 |
|
eqid |
⊢ ( 0g ‘ 𝑅 ) = ( 0g ‘ 𝑅 ) |
9 |
2 8
|
nzrunit |
⊢ ( ( 𝑅 ∈ NzRing ∧ ( ( invg ‘ 𝑅 ) ‘ ( 1r ‘ 𝑅 ) ) ∈ ( Unit ‘ 𝑅 ) ) → ( ( invg ‘ 𝑅 ) ‘ ( 1r ‘ 𝑅 ) ) ≠ ( 0g ‘ 𝑅 ) ) |
10 |
7 9
|
mpdan |
⊢ ( 𝑅 ∈ NzRing → ( ( invg ‘ 𝑅 ) ‘ ( 1r ‘ 𝑅 ) ) ≠ ( 0g ‘ 𝑅 ) ) |