Description: Any relation is a partial order on the empty set. (Contributed by NM, 28-Mar-1997) (Proof shortened by Andrew Salmon, 25-Jul-2011)
Ref | Expression | ||
---|---|---|---|
Assertion | po0 | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ral0 | |
|
2 | df-po | |
|
3 | 1 2 | mpbir | |