Theorem hvsubvali

Description: Value of vector subtraction definition. (Contributed by NM, 3-Sep-1999) (New usage is discouraged.)

	Ref	Expression
Hypotheses	hvaddcl.1	⊢ 𝐴 ∈ ℋ
	hvaddcl.2	⊢ 𝐵 ∈ ℋ
Assertion	hvsubvali	⊢ ( 𝐴 −ℎ 𝐵 ) = ( 𝐴 +ℎ ( - 1 ·ℎ 𝐵 ) )

Proof

Step	Hyp	Ref	Expression
1		hvaddcl.1	⊢ 𝐴 ∈ ℋ
2		hvaddcl.2	⊢ 𝐵 ∈ ℋ
3		hvsubval	⊢ ( ( 𝐴 ∈ ℋ ∧ 𝐵 ∈ ℋ ) → ( 𝐴 −ℎ 𝐵 ) = ( 𝐴 +ℎ ( - 1 ·ℎ 𝐵 ) ) )
4	1 2 3	mp2an	⊢ ( 𝐴 −ℎ 𝐵 ) = ( 𝐴 +ℎ ( - 1 ·ℎ 𝐵 ) )