Description: Importation from double to triple conjunction. (Contributed by NM, 20-Aug-1995)
Ref | Expression | ||
---|---|---|---|
Hypothesis | 3impb.1 | |
|
Assertion | 3impb | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 3impb.1 | |
|
2 | 1 | exp32 | |
3 | 2 | 3imp | |