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Description: Lemma for prter1 , prter2 and prtex . (Contributed by Rodolfo Medina, 13-Oct-2010)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | prtlem14 | |- ( Prt A -> ( ( x e. A /\ y e. A ) -> ( ( w e. x /\ w e. y ) -> x = y ) ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | df-prt | |- ( Prt A <-> A. x e. A A. y e. A ( x = y \/ ( x i^i y ) = (/) ) ) |
|
| 2 | rsp2 | |- ( A. x e. A A. y e. A ( x = y \/ ( x i^i y ) = (/) ) -> ( ( x e. A /\ y e. A ) -> ( x = y \/ ( x i^i y ) = (/) ) ) ) |
|
| 3 | 1 2 | sylbi | |- ( Prt A -> ( ( x e. A /\ y e. A ) -> ( x = y \/ ( x i^i y ) = (/) ) ) ) |
| 4 | elin | |- ( w e. ( x i^i y ) <-> ( w e. x /\ w e. y ) ) |
|
| 5 | eq0 | |- ( ( x i^i y ) = (/) <-> A. w -. w e. ( x i^i y ) ) |
|
| 6 | sp | |- ( A. w -. w e. ( x i^i y ) -> -. w e. ( x i^i y ) ) |
|
| 7 | 5 6 | sylbi | |- ( ( x i^i y ) = (/) -> -. w e. ( x i^i y ) ) |
| 8 | 7 | pm2.21d | |- ( ( x i^i y ) = (/) -> ( w e. ( x i^i y ) -> x = y ) ) |
| 9 | 4 8 | biimtrrid | |- ( ( x i^i y ) = (/) -> ( ( w e. x /\ w e. y ) -> x = y ) ) |
| 10 | 9 | jao1i | |- ( ( x = y \/ ( x i^i y ) = (/) ) -> ( ( w e. x /\ w e. y ) -> x = y ) ) |
| 11 | 3 10 | syl6 | |- ( Prt A -> ( ( x e. A /\ y e. A ) -> ( ( w e. x /\ w e. y ) -> x = y ) ) ) |