Description: Swap second and third argument of double difference. (Contributed by NM, 18-Aug-2004)
Ref | Expression | ||
---|---|---|---|
Assertion | dif32 | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | uncom | |
|
2 | 1 | difeq2i | |
3 | difun1 | |
|
4 | difun1 | |
|
5 | 2 3 4 | 3eqtr3i | |