| Step |
Hyp |
Ref |
Expression |
| 1 |
|
addmuldir1d.a |
|- ( ph -> A e. CC ) |
| 2 |
|
addmuldir1d.b |
|- ( ph -> B e. CC ) |
| 3 |
|
addmuldir1d.c |
|- ( ph -> C e. CC ) |
| 4 |
|
addmuldir1d.d |
|- ( ph -> D e. CC ) |
| 5 |
|
addmuldir1d.e |
|- ( ph -> E e. CC ) |
| 6 |
|
addmuldir1d.f |
|- ( ph -> F e. CC ) |
| 7 |
2 3
|
mulcld |
|- ( ph -> ( B x. C ) e. CC ) |
| 8 |
5 6
|
mulcld |
|- ( ph -> ( E x. F ) e. CC ) |
| 9 |
1 7 4 8
|
muladdd |
|- ( ph -> ( ( A + ( B x. C ) ) x. ( D + ( E x. F ) ) ) = ( ( ( A x. D ) + ( ( E x. F ) x. ( B x. C ) ) ) + ( ( A x. ( E x. F ) ) + ( D x. ( B x. C ) ) ) ) ) |
| 10 |
1 4
|
mulcld |
|- ( ph -> ( A x. D ) e. CC ) |
| 11 |
8 7
|
mulcld |
|- ( ph -> ( ( E x. F ) x. ( B x. C ) ) e. CC ) |
| 12 |
1 8
|
mulcld |
|- ( ph -> ( A x. ( E x. F ) ) e. CC ) |
| 13 |
4 7
|
mulcld |
|- ( ph -> ( D x. ( B x. C ) ) e. CC ) |
| 14 |
10 11 12 13
|
add42d |
|- ( ph -> ( ( ( A x. D ) + ( ( E x. F ) x. ( B x. C ) ) ) + ( ( A x. ( E x. F ) ) + ( D x. ( B x. C ) ) ) ) = ( ( ( A x. D ) + ( A x. ( E x. F ) ) ) + ( ( D x. ( B x. C ) ) + ( ( E x. F ) x. ( B x. C ) ) ) ) ) |
| 15 |
8 7
|
mulcomd |
|- ( ph -> ( ( E x. F ) x. ( B x. C ) ) = ( ( B x. C ) x. ( E x. F ) ) ) |
| 16 |
15
|
oveq2d |
|- ( ph -> ( ( D x. ( B x. C ) ) + ( ( E x. F ) x. ( B x. C ) ) ) = ( ( D x. ( B x. C ) ) + ( ( B x. C ) x. ( E x. F ) ) ) ) |
| 17 |
16
|
oveq2d |
|- ( ph -> ( ( ( A x. D ) + ( A x. ( E x. F ) ) ) + ( ( D x. ( B x. C ) ) + ( ( E x. F ) x. ( B x. C ) ) ) ) = ( ( ( A x. D ) + ( A x. ( E x. F ) ) ) + ( ( D x. ( B x. C ) ) + ( ( B x. C ) x. ( E x. F ) ) ) ) ) |
| 18 |
9 14 17
|
3eqtrd |
|- ( ph -> ( ( A + ( B x. C ) ) x. ( D + ( E x. F ) ) ) = ( ( ( A x. D ) + ( A x. ( E x. F ) ) ) + ( ( D x. ( B x. C ) ) + ( ( B x. C ) x. ( E x. F ) ) ) ) ) |