Description: Exportation deduction for triple conjunction. (Contributed by NM, 26-Oct-2006)
Ref | Expression | ||
---|---|---|---|
Hypothesis | 3expd.1 | |
|
Assertion | 3expd | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 3expd.1 | |
|
2 | 1 | com12 | |
3 | 2 | 3exp | |
4 | 3 | com4r | |