Metamath Proof Explorer


Theorem cnmpt2mulr

Description: Continuity of ring multiplication; analogue of cnmpt22f which cannot be used directly because .r is not a function. (Contributed by Mario Carneiro, 5-Oct-2015)

Ref Expression
Hypotheses mulrcn.j 𝐽 = ( TopOpen ‘ 𝑅 )
cnmpt1mulr.t · = ( .r𝑅 )
cnmpt1mulr.r ( 𝜑𝑅 ∈ TopRing )
cnmpt1mulr.k ( 𝜑𝐾 ∈ ( TopOn ‘ 𝑋 ) )
cnmpt2mulr.l ( 𝜑𝐿 ∈ ( TopOn ‘ 𝑌 ) )
cnmpt2mulr.a ( 𝜑 → ( 𝑥𝑋 , 𝑦𝑌𝐴 ) ∈ ( ( 𝐾 ×t 𝐿 ) Cn 𝐽 ) )
cnmpt2mulr.b ( 𝜑 → ( 𝑥𝑋 , 𝑦𝑌𝐵 ) ∈ ( ( 𝐾 ×t 𝐿 ) Cn 𝐽 ) )
Assertion cnmpt2mulr ( 𝜑 → ( 𝑥𝑋 , 𝑦𝑌 ↦ ( 𝐴 · 𝐵 ) ) ∈ ( ( 𝐾 ×t 𝐿 ) Cn 𝐽 ) )

Proof

Step Hyp Ref Expression
1 mulrcn.j 𝐽 = ( TopOpen ‘ 𝑅 )
2 cnmpt1mulr.t · = ( .r𝑅 )
3 cnmpt1mulr.r ( 𝜑𝑅 ∈ TopRing )
4 cnmpt1mulr.k ( 𝜑𝐾 ∈ ( TopOn ‘ 𝑋 ) )
5 cnmpt2mulr.l ( 𝜑𝐿 ∈ ( TopOn ‘ 𝑌 ) )
6 cnmpt2mulr.a ( 𝜑 → ( 𝑥𝑋 , 𝑦𝑌𝐴 ) ∈ ( ( 𝐾 ×t 𝐿 ) Cn 𝐽 ) )
7 cnmpt2mulr.b ( 𝜑 → ( 𝑥𝑋 , 𝑦𝑌𝐵 ) ∈ ( ( 𝐾 ×t 𝐿 ) Cn 𝐽 ) )
8 eqid ( mulGrp ‘ 𝑅 ) = ( mulGrp ‘ 𝑅 )
9 8 1 mgptopn 𝐽 = ( TopOpen ‘ ( mulGrp ‘ 𝑅 ) )
10 8 2 mgpplusg · = ( +g ‘ ( mulGrp ‘ 𝑅 ) )
11 8 trgtmd ( 𝑅 ∈ TopRing → ( mulGrp ‘ 𝑅 ) ∈ TopMnd )
12 3 11 syl ( 𝜑 → ( mulGrp ‘ 𝑅 ) ∈ TopMnd )
13 9 10 12 4 5 6 7 cnmpt2plusg ( 𝜑 → ( 𝑥𝑋 , 𝑦𝑌 ↦ ( 𝐴 · 𝐵 ) ) ∈ ( ( 𝐾 ×t 𝐿 ) Cn 𝐽 ) )