Description: Reciprocal of reciprocal of positive fraction. (Contributed by NM, 26-Apr-1996) (Revised by Mario Carneiro, 29-Apr-2013) (New usage is discouraged.)
Ref | Expression | ||
---|---|---|---|
Assertion | recrecnq | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 2fveq3 | |
|
2 | id | |
|
3 | 1 2 | eqeq12d | |
4 | mulcomnq | |
|
5 | recidnq | |
|
6 | 4 5 | eqtrid | |
7 | recclnq | |
|
8 | recmulnq | |
|
9 | 7 8 | syl | |
10 | 6 9 | mpbird | |
11 | 3 10 | vtoclga | |