Metamath Proof Explorer


Theorem rngomndo

Description: In a unital ring the multiplication is a monoid. (Contributed by FL, 24-Jan-2010) (Revised by Mario Carneiro, 22-Dec-2013) (New usage is discouraged.)

Ref Expression
Hypothesis unmnd.1 𝐻 = ( 2nd𝑅 )
Assertion rngomndo ( 𝑅 ∈ RingOps → 𝐻 ∈ MndOp )

Proof

Step Hyp Ref Expression
1 unmnd.1 𝐻 = ( 2nd𝑅 )
2 eqid ( 1st𝑅 ) = ( 1st𝑅 )
3 eqid ran ( 1st𝑅 ) = ran ( 1st𝑅 )
4 2 1 3 rngosm ( 𝑅 ∈ RingOps → 𝐻 : ( ran ( 1st𝑅 ) × ran ( 1st𝑅 ) ) ⟶ ran ( 1st𝑅 ) )
5 2 1 3 rngoass ( ( 𝑅 ∈ RingOps ∧ ( 𝑥 ∈ ran ( 1st𝑅 ) ∧ 𝑦 ∈ ran ( 1st𝑅 ) ∧ 𝑧 ∈ ran ( 1st𝑅 ) ) ) → ( ( 𝑥 𝐻 𝑦 ) 𝐻 𝑧 ) = ( 𝑥 𝐻 ( 𝑦 𝐻 𝑧 ) ) )
6 5 ralrimivvva ( 𝑅 ∈ RingOps → ∀ 𝑥 ∈ ran ( 1st𝑅 ) ∀ 𝑦 ∈ ran ( 1st𝑅 ) ∀ 𝑧 ∈ ran ( 1st𝑅 ) ( ( 𝑥 𝐻 𝑦 ) 𝐻 𝑧 ) = ( 𝑥 𝐻 ( 𝑦 𝐻 𝑧 ) ) )
7 2 1 3 rngoi ( 𝑅 ∈ RingOps → ( ( ( 1st𝑅 ) ∈ AbelOp ∧ 𝐻 : ( ran ( 1st𝑅 ) × ran ( 1st𝑅 ) ) ⟶ ran ( 1st𝑅 ) ) ∧ ( ∀ 𝑥 ∈ ran ( 1st𝑅 ) ∀ 𝑦 ∈ ran ( 1st𝑅 ) ∀ 𝑧 ∈ ran ( 1st𝑅 ) ( ( ( 𝑥 𝐻 𝑦 ) 𝐻 𝑧 ) = ( 𝑥 𝐻 ( 𝑦 𝐻 𝑧 ) ) ∧ ( 𝑥 𝐻 ( 𝑦 ( 1st𝑅 ) 𝑧 ) ) = ( ( 𝑥 𝐻 𝑦 ) ( 1st𝑅 ) ( 𝑥 𝐻 𝑧 ) ) ∧ ( ( 𝑥 ( 1st𝑅 ) 𝑦 ) 𝐻 𝑧 ) = ( ( 𝑥 𝐻 𝑧 ) ( 1st𝑅 ) ( 𝑦 𝐻 𝑧 ) ) ) ∧ ∃ 𝑥 ∈ ran ( 1st𝑅 ) ∀ 𝑦 ∈ ran ( 1st𝑅 ) ( ( 𝑥 𝐻 𝑦 ) = 𝑦 ∧ ( 𝑦 𝐻 𝑥 ) = 𝑦 ) ) ) )
8 7 simprrd ( 𝑅 ∈ RingOps → ∃ 𝑥 ∈ ran ( 1st𝑅 ) ∀ 𝑦 ∈ ran ( 1st𝑅 ) ( ( 𝑥 𝐻 𝑦 ) = 𝑦 ∧ ( 𝑦 𝐻 𝑥 ) = 𝑦 ) )
9 1 2 rngorn1 ( 𝑅 ∈ RingOps → ran ( 1st𝑅 ) = dom dom 𝐻 )
10 xpid11 ( ( dom dom 𝐻 × dom dom 𝐻 ) = ( ran ( 1st𝑅 ) × ran ( 1st𝑅 ) ) ↔ dom dom 𝐻 = ran ( 1st𝑅 ) )
11 10 biimpri ( dom dom 𝐻 = ran ( 1st𝑅 ) → ( dom dom 𝐻 × dom dom 𝐻 ) = ( ran ( 1st𝑅 ) × ran ( 1st𝑅 ) ) )
12 feq23 ( ( ( dom dom 𝐻 × dom dom 𝐻 ) = ( ran ( 1st𝑅 ) × ran ( 1st𝑅 ) ) ∧ dom dom 𝐻 = ran ( 1st𝑅 ) ) → ( 𝐻 : ( dom dom 𝐻 × dom dom 𝐻 ) ⟶ dom dom 𝐻𝐻 : ( ran ( 1st𝑅 ) × ran ( 1st𝑅 ) ) ⟶ ran ( 1st𝑅 ) ) )
13 11 12 mpancom ( dom dom 𝐻 = ran ( 1st𝑅 ) → ( 𝐻 : ( dom dom 𝐻 × dom dom 𝐻 ) ⟶ dom dom 𝐻𝐻 : ( ran ( 1st𝑅 ) × ran ( 1st𝑅 ) ) ⟶ ran ( 1st𝑅 ) ) )
14 raleq ( dom dom 𝐻 = ran ( 1st𝑅 ) → ( ∀ 𝑧 ∈ dom dom 𝐻 ( ( 𝑥 𝐻 𝑦 ) 𝐻 𝑧 ) = ( 𝑥 𝐻 ( 𝑦 𝐻 𝑧 ) ) ↔ ∀ 𝑧 ∈ ran ( 1st𝑅 ) ( ( 𝑥 𝐻 𝑦 ) 𝐻 𝑧 ) = ( 𝑥 𝐻 ( 𝑦 𝐻 𝑧 ) ) ) )
15 14 raleqbi1dv ( dom dom 𝐻 = ran ( 1st𝑅 ) → ( ∀ 𝑦 ∈ dom dom 𝐻𝑧 ∈ dom dom 𝐻 ( ( 𝑥 𝐻 𝑦 ) 𝐻 𝑧 ) = ( 𝑥 𝐻 ( 𝑦 𝐻 𝑧 ) ) ↔ ∀ 𝑦 ∈ ran ( 1st𝑅 ) ∀ 𝑧 ∈ ran ( 1st𝑅 ) ( ( 𝑥 𝐻 𝑦 ) 𝐻 𝑧 ) = ( 𝑥 𝐻 ( 𝑦 𝐻 𝑧 ) ) ) )
16 15 raleqbi1dv ( dom dom 𝐻 = ran ( 1st𝑅 ) → ( ∀ 𝑥 ∈ dom dom 𝐻𝑦 ∈ dom dom 𝐻𝑧 ∈ dom dom 𝐻 ( ( 𝑥 𝐻 𝑦 ) 𝐻 𝑧 ) = ( 𝑥 𝐻 ( 𝑦 𝐻 𝑧 ) ) ↔ ∀ 𝑥 ∈ ran ( 1st𝑅 ) ∀ 𝑦 ∈ ran ( 1st𝑅 ) ∀ 𝑧 ∈ ran ( 1st𝑅 ) ( ( 𝑥 𝐻 𝑦 ) 𝐻 𝑧 ) = ( 𝑥 𝐻 ( 𝑦 𝐻 𝑧 ) ) ) )
17 raleq ( dom dom 𝐻 = ran ( 1st𝑅 ) → ( ∀ 𝑦 ∈ dom dom 𝐻 ( ( 𝑥 𝐻 𝑦 ) = 𝑦 ∧ ( 𝑦 𝐻 𝑥 ) = 𝑦 ) ↔ ∀ 𝑦 ∈ ran ( 1st𝑅 ) ( ( 𝑥 𝐻 𝑦 ) = 𝑦 ∧ ( 𝑦 𝐻 𝑥 ) = 𝑦 ) ) )
18 17 rexeqbi1dv ( dom dom 𝐻 = ran ( 1st𝑅 ) → ( ∃ 𝑥 ∈ dom dom 𝐻𝑦 ∈ dom dom 𝐻 ( ( 𝑥 𝐻 𝑦 ) = 𝑦 ∧ ( 𝑦 𝐻 𝑥 ) = 𝑦 ) ↔ ∃ 𝑥 ∈ ran ( 1st𝑅 ) ∀ 𝑦 ∈ ran ( 1st𝑅 ) ( ( 𝑥 𝐻 𝑦 ) = 𝑦 ∧ ( 𝑦 𝐻 𝑥 ) = 𝑦 ) ) )
19 13 16 18 3anbi123d ( dom dom 𝐻 = ran ( 1st𝑅 ) → ( ( 𝐻 : ( dom dom 𝐻 × dom dom 𝐻 ) ⟶ dom dom 𝐻 ∧ ∀ 𝑥 ∈ dom dom 𝐻𝑦 ∈ dom dom 𝐻𝑧 ∈ dom dom 𝐻 ( ( 𝑥 𝐻 𝑦 ) 𝐻 𝑧 ) = ( 𝑥 𝐻 ( 𝑦 𝐻 𝑧 ) ) ∧ ∃ 𝑥 ∈ dom dom 𝐻𝑦 ∈ dom dom 𝐻 ( ( 𝑥 𝐻 𝑦 ) = 𝑦 ∧ ( 𝑦 𝐻 𝑥 ) = 𝑦 ) ) ↔ ( 𝐻 : ( ran ( 1st𝑅 ) × ran ( 1st𝑅 ) ) ⟶ ran ( 1st𝑅 ) ∧ ∀ 𝑥 ∈ ran ( 1st𝑅 ) ∀ 𝑦 ∈ ran ( 1st𝑅 ) ∀ 𝑧 ∈ ran ( 1st𝑅 ) ( ( 𝑥 𝐻 𝑦 ) 𝐻 𝑧 ) = ( 𝑥 𝐻 ( 𝑦 𝐻 𝑧 ) ) ∧ ∃ 𝑥 ∈ ran ( 1st𝑅 ) ∀ 𝑦 ∈ ran ( 1st𝑅 ) ( ( 𝑥 𝐻 𝑦 ) = 𝑦 ∧ ( 𝑦 𝐻 𝑥 ) = 𝑦 ) ) ) )
20 19 eqcoms ( ran ( 1st𝑅 ) = dom dom 𝐻 → ( ( 𝐻 : ( dom dom 𝐻 × dom dom 𝐻 ) ⟶ dom dom 𝐻 ∧ ∀ 𝑥 ∈ dom dom 𝐻𝑦 ∈ dom dom 𝐻𝑧 ∈ dom dom 𝐻 ( ( 𝑥 𝐻 𝑦 ) 𝐻 𝑧 ) = ( 𝑥 𝐻 ( 𝑦 𝐻 𝑧 ) ) ∧ ∃ 𝑥 ∈ dom dom 𝐻𝑦 ∈ dom dom 𝐻 ( ( 𝑥 𝐻 𝑦 ) = 𝑦 ∧ ( 𝑦 𝐻 𝑥 ) = 𝑦 ) ) ↔ ( 𝐻 : ( ran ( 1st𝑅 ) × ran ( 1st𝑅 ) ) ⟶ ran ( 1st𝑅 ) ∧ ∀ 𝑥 ∈ ran ( 1st𝑅 ) ∀ 𝑦 ∈ ran ( 1st𝑅 ) ∀ 𝑧 ∈ ran ( 1st𝑅 ) ( ( 𝑥 𝐻 𝑦 ) 𝐻 𝑧 ) = ( 𝑥 𝐻 ( 𝑦 𝐻 𝑧 ) ) ∧ ∃ 𝑥 ∈ ran ( 1st𝑅 ) ∀ 𝑦 ∈ ran ( 1st𝑅 ) ( ( 𝑥 𝐻 𝑦 ) = 𝑦 ∧ ( 𝑦 𝐻 𝑥 ) = 𝑦 ) ) ) )
21 9 20 syl ( 𝑅 ∈ RingOps → ( ( 𝐻 : ( dom dom 𝐻 × dom dom 𝐻 ) ⟶ dom dom 𝐻 ∧ ∀ 𝑥 ∈ dom dom 𝐻𝑦 ∈ dom dom 𝐻𝑧 ∈ dom dom 𝐻 ( ( 𝑥 𝐻 𝑦 ) 𝐻 𝑧 ) = ( 𝑥 𝐻 ( 𝑦 𝐻 𝑧 ) ) ∧ ∃ 𝑥 ∈ dom dom 𝐻𝑦 ∈ dom dom 𝐻 ( ( 𝑥 𝐻 𝑦 ) = 𝑦 ∧ ( 𝑦 𝐻 𝑥 ) = 𝑦 ) ) ↔ ( 𝐻 : ( ran ( 1st𝑅 ) × ran ( 1st𝑅 ) ) ⟶ ran ( 1st𝑅 ) ∧ ∀ 𝑥 ∈ ran ( 1st𝑅 ) ∀ 𝑦 ∈ ran ( 1st𝑅 ) ∀ 𝑧 ∈ ran ( 1st𝑅 ) ( ( 𝑥 𝐻 𝑦 ) 𝐻 𝑧 ) = ( 𝑥 𝐻 ( 𝑦 𝐻 𝑧 ) ) ∧ ∃ 𝑥 ∈ ran ( 1st𝑅 ) ∀ 𝑦 ∈ ran ( 1st𝑅 ) ( ( 𝑥 𝐻 𝑦 ) = 𝑦 ∧ ( 𝑦 𝐻 𝑥 ) = 𝑦 ) ) ) )
22 4 6 8 21 mpbir3and ( 𝑅 ∈ RingOps → ( 𝐻 : ( dom dom 𝐻 × dom dom 𝐻 ) ⟶ dom dom 𝐻 ∧ ∀ 𝑥 ∈ dom dom 𝐻𝑦 ∈ dom dom 𝐻𝑧 ∈ dom dom 𝐻 ( ( 𝑥 𝐻 𝑦 ) 𝐻 𝑧 ) = ( 𝑥 𝐻 ( 𝑦 𝐻 𝑧 ) ) ∧ ∃ 𝑥 ∈ dom dom 𝐻𝑦 ∈ dom dom 𝐻 ( ( 𝑥 𝐻 𝑦 ) = 𝑦 ∧ ( 𝑦 𝐻 𝑥 ) = 𝑦 ) ) )
23 fvex ( 2nd𝑅 ) ∈ V
24 eleq1 ( 𝐻 = ( 2nd𝑅 ) → ( 𝐻 ∈ V ↔ ( 2nd𝑅 ) ∈ V ) )
25 23 24 mpbiri ( 𝐻 = ( 2nd𝑅 ) → 𝐻 ∈ V )
26 eqid dom dom 𝐻 = dom dom 𝐻
27 26 ismndo1 ( 𝐻 ∈ V → ( 𝐻 ∈ MndOp ↔ ( 𝐻 : ( dom dom 𝐻 × dom dom 𝐻 ) ⟶ dom dom 𝐻 ∧ ∀ 𝑥 ∈ dom dom 𝐻𝑦 ∈ dom dom 𝐻𝑧 ∈ dom dom 𝐻 ( ( 𝑥 𝐻 𝑦 ) 𝐻 𝑧 ) = ( 𝑥 𝐻 ( 𝑦 𝐻 𝑧 ) ) ∧ ∃ 𝑥 ∈ dom dom 𝐻𝑦 ∈ dom dom 𝐻 ( ( 𝑥 𝐻 𝑦 ) = 𝑦 ∧ ( 𝑦 𝐻 𝑥 ) = 𝑦 ) ) ) )
28 1 25 27 mp2b ( 𝐻 ∈ MndOp ↔ ( 𝐻 : ( dom dom 𝐻 × dom dom 𝐻 ) ⟶ dom dom 𝐻 ∧ ∀ 𝑥 ∈ dom dom 𝐻𝑦 ∈ dom dom 𝐻𝑧 ∈ dom dom 𝐻 ( ( 𝑥 𝐻 𝑦 ) 𝐻 𝑧 ) = ( 𝑥 𝐻 ( 𝑦 𝐻 𝑧 ) ) ∧ ∃ 𝑥 ∈ dom dom 𝐻𝑦 ∈ dom dom 𝐻 ( ( 𝑥 𝐻 𝑦 ) = 𝑦 ∧ ( 𝑦 𝐻 𝑥 ) = 𝑦 ) ) )
29 22 28 sylibr ( 𝑅 ∈ RingOps → 𝐻 ∈ MndOp )