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Related theorems Unicode version |
| Description: An inference from transitive law for logical equivalence. (The proof was shortened by Wolf Lammen, 13-Oct-2012.) |
| Ref | Expression |
|---|---|
| bitri.1 |
|
| bitri.2 |
|
| Ref | Expression |
|---|---|
| bitri |
|
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | bitri.1 |
. . . 4
| |
| 2 | 1 | biimpi 224 |
. . 3
|
| 3 | bitri.2 |
. . 3
| |
| 4 | 2, 3 | sylib 242 |
. 2
|
| 5 | 3 | biimpri 230 |
. . 3
|
| 6 | 5, 1 | sylibr 243 |
. 2
|
| 7 | 4, 6 | impbii 223 |
1
|