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Description: Infer implication from a logical equivalence. Similar to biimpa . (Contributed by NM, 4-Sep-2005)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | biimp3a.1 | ||
| Assertion | biimp3a |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | biimp3a.1 | ||
| 2 | 1 | biimpa | |
| 3 | 2 | 3impa |