Metamath Proof Explorer
Description: "At most one" remains true inside ordered pair quantification.
(Contributed by NM, 28-May-1995)
|
|
Ref |
Expression |
|
Hypothesis |
mosubop.1 |
|
|
Assertion |
mosubop |
|
Proof
Step |
Hyp |
Ref |
Expression |
1 |
|
mosubop.1 |
|
2 |
1
|
gen2 |
|
3 |
|
mosubopt |
|
4 |
2 3
|
ax-mp |
|