| Metamath Proof Explorer |
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Related theorems Unicode version |
| Description: Introduce a left conjunct to both sides of a logical equivalence. |
| Ref | Expression |
|---|---|
| bi.aa |
|
| Ref | Expression |
|---|---|
| anbi2i |
|
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | bi.aa |
. . . 4
| |
| 2 | 1 | biimpi 168 |
. . 3
|
| 3 | 2 | anim2i 362 |
. 2
|
| 4 | 1 | biimpri 169 |
. . 3
|
| 5 | 4 | anim2i 362 |
. 2
|
| 6 | 3, 5 | impbii 174 |
1
|