Description: A lexicographical ordering of two well-founded classes. (Contributed by Scott Fenton, 17-Mar-2011) (Revised by Mario Carneiro, 7-Mar-2013) (Proof shortened by Wolf Lammen, 4-Oct-2014)
Ref | Expression | ||
---|---|---|---|
Hypothesis | frxp.1 | |
|
Assertion | frxp | |