Metamath Proof Explorer


Theorem cnmpt1mulr

Description: Continuity of ring multiplication; analogue of cnmpt12f 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 ⊢ · ˙ = ⋅ R
cnmpt1mulr.r ⊢ φ → R ∈ TopRing
cnmpt1mulr.k ⊢ φ → K ∈ TopOn ⁡ X
cnmpt1mulr.a ⊢ φ → x ∈ X ⟼ A ∈ K Cn J
cnmpt1mulr.b ⊢ φ → x ∈ X ⟼ B ∈ K Cn J
Assertion cnmpt1mulr ⊢ φ → x ∈ X ⟼ A · ˙ B ∈ K Cn J

Proof

Step Hyp Ref Expression
1 mulrcn.j ⊢ J = TopOpen ⁡ R
2 cnmpt1mulr.t ⊢ · ˙ = ⋅ R
3 cnmpt1mulr.r ⊢ φ → R ∈ TopRing
4 cnmpt1mulr.k ⊢ φ → K ∈ TopOn ⁡ X
5 cnmpt1mulr.a ⊢ φ → x ∈ X ⟼ A ∈ K Cn J
6 cnmpt1mulr.b ⊢ φ → x ∈ X ⟼ B ∈ K Cn J
7 eqid ⊢ mulGrp R = mulGrp R
8 7 1 mgptopn ⊢ J = TopOpen ⁡ mulGrp R
9 7 2 mgpplusg ⊢ · ˙ = + mulGrp R
10 7 trgtmd ⊢ R ∈ TopRing → mulGrp R ∈ TopMnd
11 3 10 syl ⊢ φ → mulGrp R ∈ TopMnd
12 8 9 11 4 5 6 cnmpt1plusg ⊢ φ → x ∈ X ⟼ A · ˙ B ∈ K Cn J