Description: Associative law for inner product. Equation I2 of Ponnusamy p. 363. (Contributed by NM, 25-Aug-2007) (New usage is discouraged.)
Ref | Expression | ||
---|---|---|---|
Hypotheses | ipass.1 | |
|
ipass.4 | |
||
ipass.7 | |
||
Assertion | dipass | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ipass.1 | |
|
2 | ipass.4 | |
|
3 | ipass.7 | |
|
4 | fveq2 | |
|
5 | 1 4 | eqtrid | |
6 | 5 | eleq2d | |
7 | 5 | eleq2d | |
8 | 6 7 | 3anbi23d | |
9 | fveq2 | |
|
10 | 2 9 | eqtrid | |
11 | 10 | oveqd | |
12 | 11 | oveq1d | |
13 | fveq2 | |
|
14 | 3 13 | eqtrid | |
15 | 14 | oveqd | |
16 | 12 15 | eqtrd | |
17 | 14 | oveqd | |
18 | 17 | oveq2d | |
19 | 16 18 | eqeq12d | |
20 | 8 19 | imbi12d | |
21 | eqid | |
|
22 | eqid | |
|
23 | eqid | |
|
24 | eqid | |
|
25 | elimphu | |
|
26 | 21 22 23 24 25 | ipassi | |
27 | 20 26 | dedth | |
28 | 27 | imp | |