Description: The class of all ordinal numbers is its own union. Exercise 11 of TakeutiZaring p. 40. (Contributed by NM, 12-Nov-2003)
Ref | Expression | ||
---|---|---|---|
Assertion | unon | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | eluni2 | |
|
2 | onelon | |
|
3 | 2 | rexlimiva | |
4 | 1 3 | sylbi | |
5 | vex | |
|
6 | 5 | sucid | |
7 | suceloni | |
|
8 | elunii | |
|
9 | 6 7 8 | sylancr | |
10 | 4 9 | impbii | |
11 | 10 | eqriv | |