Description: Vector addition is associative. (Contributed by NM, 3-Sep-1999) (New usage is discouraged.)
Ref | Expression | ||
---|---|---|---|
Assertion | ax-hvass | |- ( ( A e. ~H /\ B e. ~H /\ C e. ~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 e. ~H |
3 | cB | |- B |
|
4 | 3 1 | wcel | |- B e. ~H |
5 | cC | |- C |
|
6 | 5 1 | wcel | |- C e. ~H |
7 | 2 4 6 | w3a | |- ( A e. ~H /\ B e. ~H /\ C e. ~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 e. ~H /\ B e. ~H /\ C e. ~H ) -> ( ( A +h B ) +h C ) = ( A +h ( B +h C ) ) ) |