Description: A set whose successor is a subset of another class is a member of that class. (Contributed by NM, 16-Sep-1995)
Ref | Expression | ||
---|---|---|---|
Assertion | sucssel | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | sucidg | |
|
2 | ssel | |
|
3 | 1 2 | syl5com | |