Description: First-order logic and set theory. (Contributed by Jonathan Ben-Naim, 3-Jun-2011) (New usage is discouraged.)
Ref | Expression | ||
---|---|---|---|
Assertion | bnj219 | |- ( n = suc m -> m _E n ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | vex | |- m e. _V |
|
2 | 1 | bnj216 | |- ( n = suc m -> m e. n ) |
3 | epel | |- ( m _E n <-> m e. n ) |
|
4 | 2 3 | sylibr | |- ( n = suc m -> m _E n ) |