Metamath Proof Explorer
Description: Commutation in antecedent. Swap 2nd and 3rd. (Contributed by NM, 28-Jan-1996) (Proof shortened by Wolf Lammen, 9-Apr-2022)
|
|
Ref |
Expression |
|
Hypothesis |
3exp.1 |
|
|
Assertion |
3com23 |
|
Proof
Step |
Hyp |
Ref |
Expression |
1 |
|
3exp.1 |
|
2 |
1
|
3comr |
|
3 |
2
|
3com12 |
|