∀ {X : Type u_1} {m : Type u_4} {n : Type u_5} {R : Type u_8} [inst : TopologicalSpace X] [inst_1 : TopologicalSpace R]
  [inst_2 : Mul R] [ContinuousMul R] {A : X → m → R} {B : X → n → R},
  Continuous A → Continuous B → Continuous fun x => Matrix.vecMulVec (A x) (B x)