Description: Swap two conjuncts in antecedent. (Contributed by NM, 31-May-2006)
Ref | Expression | ||
---|---|---|---|
Hypothesis | an12s.1 | |
|
Assertion | an13s | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | an12s.1 | |
|
2 | 1 | exp32 | |
3 | 2 | com13 | |
4 | 3 | imp32 | |