Metamath Proof Explorer


Theorem imasmulf

Description: The image structure's ring multiplication is closed in the base set. (Contributed by Mario Carneiro, 23-Feb-2015)

Ref Expression
Hypotheses imasaddf.f ⊢ ( 𝜑 → 𝐹 : 𝑉 –onto→ 𝐵 )
imasaddf.e ⊢ ( ( 𝜑 ∧ ( 𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉 ) ∧ ( 𝑝 ∈ 𝑉 ∧ 𝑞 ∈ 𝑉 ) ) → ( ( ( 𝐹 ‘ 𝑎 ) = ( 𝐹 ‘ 𝑝 ) ∧ ( 𝐹 ‘ 𝑏 ) = ( 𝐹 ‘ 𝑞 ) ) → ( 𝐹 ‘ ( 𝑎 · 𝑏 ) ) = ( 𝐹 ‘ ( 𝑝 · 𝑞 ) ) ) )
imasaddf.u ⊢ ( 𝜑 → 𝑈 = ( 𝐹 “s 𝑅 ) )
imasaddf.v ⊢ ( 𝜑 → 𝑉 = ( Base ‘ 𝑅 ) )
imasaddf.r ⊢ ( 𝜑 → 𝑅 ∈ 𝑍 )
imasmulf.p ⊢ · = ( .r ‘ 𝑅 )
imasmulf.a ⊢ ∙ = ( .r ‘ 𝑈 )
imasmulf.c ⊢ ( ( 𝜑 ∧ ( 𝑝 ∈ 𝑉 ∧ 𝑞 ∈ 𝑉 ) ) → ( 𝑝 · 𝑞 ) ∈ 𝑉 )
Assertion imasmulf ( 𝜑 → ∙ : ( 𝐵 × 𝐵 ) ⟶ 𝐵 )

Proof

Step Hyp Ref Expression
1 imasaddf.f ⊢ ( 𝜑 → 𝐹 : 𝑉 –onto→ 𝐵 )
2 imasaddf.e ⊢ ( ( 𝜑 ∧ ( 𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉 ) ∧ ( 𝑝 ∈ 𝑉 ∧ 𝑞 ∈ 𝑉 ) ) → ( ( ( 𝐹 ‘ 𝑎 ) = ( 𝐹 ‘ 𝑝 ) ∧ ( 𝐹 ‘ 𝑏 ) = ( 𝐹 ‘ 𝑞 ) ) → ( 𝐹 ‘ ( 𝑎 · 𝑏 ) ) = ( 𝐹 ‘ ( 𝑝 · 𝑞 ) ) ) )
3 imasaddf.u ⊢ ( 𝜑 → 𝑈 = ( 𝐹 “s 𝑅 ) )
4 imasaddf.v ⊢ ( 𝜑 → 𝑉 = ( Base ‘ 𝑅 ) )
5 imasaddf.r ⊢ ( 𝜑 → 𝑅 ∈ 𝑍 )
6 imasmulf.p ⊢ · = ( .r ‘ 𝑅 )
7 imasmulf.a ⊢ ∙ = ( .r ‘ 𝑈 )
8 imasmulf.c ⊢ ( ( 𝜑 ∧ ( 𝑝 ∈ 𝑉 ∧ 𝑞 ∈ 𝑉 ) ) → ( 𝑝 · 𝑞 ) ∈ 𝑉 )
9 3 4 1 5 6 7 imasmulr ⊢ ( 𝜑 → ∙ = ∪ 𝑝 ∈ 𝑉 ∪ 𝑞 ∈ 𝑉 { ⟨ ⟨ ( 𝐹 ‘ 𝑝 ) , ( 𝐹 ‘ 𝑞 ) ⟩ , ( 𝐹 ‘ ( 𝑝 · 𝑞 ) ) ⟩ } )
10 1 2 9 8 imasaddflem ⊢ ( 𝜑 → ∙ : ( 𝐵 × 𝐵 ) ⟶ 𝐵 )