Description: A Cartesian product is included in the ordered pair universe. Exercise 3 of TakeutiZaring p. 25. (Contributed by NM, 2-Aug-1994)
Ref | Expression | ||
---|---|---|---|
Assertion | xpss | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ssv | |
|
2 | ssv | |
|
3 | xpss12 | |
|
4 | 1 2 3 | mp2an | |