Metamath Proof Explorer


Theorem zrdivrng

Description: Obsolete theorem, use zrdrng instead. The zero ring is not a division ring. (Contributed by FL, 24-Jan-2010) (Proof shortened by Mario Carneiro, 15-Dec-2013) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Hypothesis zrdivrng.1 ⊢ A ∈ V
Assertion zrdivrng ⊢ ¬ A A A A A A ∈ DivRingOps

Proof

Step Hyp Ref Expression
1 zrdivrng.1 ⊢ A ∈ V
2 0ngrp ⊢ ¬ ∅ ∈ GrpOp
3 opex ⊢ A A ∈ V
4 3 rnsnop ⊢ ran ⁡ A A A = A
5 1 gidsn ⊢ GId ⁡ A A A = A
6 5 sneqi ⊢ GId ⁡ A A A = A
7 4 6 difeq12i ⊢ ran ⁡ A A A ∖ GId ⁡ A A A = A ∖ A
8 difid ⊢ A ∖ A = ∅
9 7 8 eqtri ⊢ ran ⁡ A A A ∖ GId ⁡ A A A = ∅
10 9 xpeq2i ⊢ ran ⁡ A A A ∖ GId ⁡ A A A × ran ⁡ A A A ∖ GId ⁡ A A A = ran ⁡ A A A ∖ GId ⁡ A A A × ∅
11 xp0 ⊢ ran ⁡ A A A ∖ GId ⁡ A A A × ∅ = ∅
12 10 11 eqtri ⊢ ran ⁡ A A A ∖ GId ⁡ A A A × ran ⁡ A A A ∖ GId ⁡ A A A = ∅
13 12 reseq2i ⊢ A A A ↾ ran ⁡ A A A ∖ GId ⁡ A A A × ran ⁡ A A A ∖ GId ⁡ A A A = A A A ↾ ∅
14 res0 ⊢ A A A ↾ ∅ = ∅
15 13 14 eqtri ⊢ A A A ↾ ran ⁡ A A A ∖ GId ⁡ A A A × ran ⁡ A A A ∖ GId ⁡ A A A = ∅
16 snex ⊢ A A A ∈ V
17 isdivrngo ⊢ A A A ∈ V → A A A A A A ∈ DivRingOps ↔ A A A A A A ∈ RingOps ∧ A A A ↾ ran ⁡ A A A ∖ GId ⁡ A A A × ran ⁡ A A A ∖ GId ⁡ A A A ∈ GrpOp
18 16 17 ax-mp ⊢ A A A A A A ∈ DivRingOps ↔ A A A A A A ∈ RingOps ∧ A A A ↾ ran ⁡ A A A ∖ GId ⁡ A A A × ran ⁡ A A A ∖ GId ⁡ A A A ∈ GrpOp
19 18 simprbi ⊢ A A A A A A ∈ DivRingOps → A A A ↾ ran ⁡ A A A ∖ GId ⁡ A A A × ran ⁡ A A A ∖ GId ⁡ A A A ∈ GrpOp
20 15 19 eqeltrrid ⊢ A A A A A A ∈ DivRingOps → ∅ ∈ GrpOp
21 2 20 mto ⊢ ¬ A A A A A A ∈ DivRingOps