Metamath Proof Explorer
Description: Commutative law for addition. (Contributed by metakunt, 25-Apr-2024)
|
|
Ref |
Expression |
|
Hypotheses |
addcomnni.1 |
|
|
|
addcomnni.2 |
|
|
Assertion |
addcomnni |
|
Proof
Step |
Hyp |
Ref |
Expression |
1 |
|
addcomnni.1 |
|
2 |
|
addcomnni.2 |
|
3 |
1
|
nncni |
|
4 |
2
|
nncni |
|
5 |
3 4
|
addcomi |
|