Description: Define reflexive relation; relation R is reflexive over the set A iff A. x e. A x R x . (Contributed by David A. Wheeler, 1-Dec-2019)
Ref | Expression | ||
---|---|---|---|
Assertion | df-reflexive | |- ( R Reflexive A <-> ( R C_ ( A X. A ) /\ A. x e. A x R x ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
0 | cR | |- R |
|
1 | cA | |- A |
|
2 | 1 0 | wreflexive | |- R Reflexive A |
3 | 1 1 | cxp | |- ( A X. A ) |
4 | 0 3 | wss | |- R C_ ( A X. A ) |
5 | vx | |- x |
|
6 | 5 | cv | |- x |
7 | 6 6 0 | wbr | |- x R x |
8 | 7 5 1 | wral | |- A. x e. A x R x |
9 | 4 8 | wa | |- ( R C_ ( A X. A ) /\ A. x e. A x R x ) |
10 | 2 9 | wb | |- ( R Reflexive A <-> ( R C_ ( A X. A ) /\ A. x e. A x R x ) ) |