Metamath Proof Explorer


Theorem rnasclmulcl

Description: (Vector) multiplication is closed for scalar multiples of the unit vector. (Contributed by SN, 5-Nov-2023)

Ref Expression
Hypotheses rnasclmulcl.c ⊢ C = algSc ⁡ W
rnasclmulcl.x ⊢ × ˙ = ⋅ W
rnasclmulcl.w ⊢ φ → W ∈ AssAlg
Assertion rnasclmulcl ⊢ φ ∧ X ∈ ran ⁡ C ∧ Y ∈ ran ⁡ C → X × ˙ Y ∈ ran ⁡ C

Proof

Step Hyp Ref Expression
1 rnasclmulcl.c ⊢ C = algSc ⁡ W
2 rnasclmulcl.x ⊢ × ˙ = ⋅ W
3 rnasclmulcl.w ⊢ φ → W ∈ AssAlg
4 1 3 rnasclsubrg ⊢ φ → ran ⁡ C ∈ SubRing ⁡ W
5 2 subrgmcl ⊢ ran ⁡ C ∈ SubRing ⁡ W ∧ X ∈ ran ⁡ C ∧ Y ∈ ran ⁡ C → X × ˙ Y ∈ ran ⁡ C
6 4 5 syl3an1 ⊢ φ ∧ X ∈ ran ⁡ C ∧ Y ∈ ran ⁡ C → X × ˙ Y ∈ ran ⁡ C
7 6 3expb ⊢ φ ∧ X ∈ ran ⁡ C ∧ Y ∈ ran ⁡ C → X × ˙ Y ∈ ran ⁡ C