Description: Vector addition is associative. (Contributed by NM, 3-Sep-1999) (New usage is discouraged.)
Ref | Expression | ||
---|---|---|---|
Assertion | ax-hvass | ⊢ ( ( 𝐴 ∈ ℋ ∧ 𝐵 ∈ ℋ ∧ 𝐶 ∈ ℋ ) → ( ( 𝐴 +ℎ 𝐵 ) +ℎ 𝐶 ) = ( 𝐴 +ℎ ( 𝐵 +ℎ 𝐶 ) ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
0 | cA | ⊢ 𝐴 | |
1 | chba | ⊢ ℋ | |
2 | 0 1 | wcel | ⊢ 𝐴 ∈ ℋ |
3 | cB | ⊢ 𝐵 | |
4 | 3 1 | wcel | ⊢ 𝐵 ∈ ℋ |
5 | cC | ⊢ 𝐶 | |
6 | 5 1 | wcel | ⊢ 𝐶 ∈ ℋ |
7 | 2 4 6 | w3a | ⊢ ( 𝐴 ∈ ℋ ∧ 𝐵 ∈ ℋ ∧ 𝐶 ∈ ℋ ) |
8 | cva | ⊢ +ℎ | |
9 | 0 3 8 | co | ⊢ ( 𝐴 +ℎ 𝐵 ) |
10 | 9 5 8 | co | ⊢ ( ( 𝐴 +ℎ 𝐵 ) +ℎ 𝐶 ) |
11 | 3 5 8 | co | ⊢ ( 𝐵 +ℎ 𝐶 ) |
12 | 0 11 8 | co | ⊢ ( 𝐴 +ℎ ( 𝐵 +ℎ 𝐶 ) ) |
13 | 10 12 | wceq | ⊢ ( ( 𝐴 +ℎ 𝐵 ) +ℎ 𝐶 ) = ( 𝐴 +ℎ ( 𝐵 +ℎ 𝐶 ) ) |
14 | 7 13 | wi | ⊢ ( ( 𝐴 ∈ ℋ ∧ 𝐵 ∈ ℋ ∧ 𝐶 ∈ ℋ ) → ( ( 𝐴 +ℎ 𝐵 ) +ℎ 𝐶 ) = ( 𝐴 +ℎ ( 𝐵 +ℎ 𝐶 ) ) ) |