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Related theorems GIF version |
| Description: Define a transitive class. Not to be confused with a transitive relation (see cotr 3528). Definition of [Enderton] p. 71 extended to arbitrary classes. For alternate definitions, see dftr2 2756 (which is suggestive of the word "transitive"), dftr3 2758, dftr4 2759, dftr5 2757, and (when A is a set) unisuc 3049. The term "complete" is used instead of "transitive" in Definition 3 of [Suppes] p. 130. |
| Ref | Expression |
|---|---|
| df-tr | ⊢ (Tr A ↔ ∪A ⊆ A) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | cA | . . 3 class A | |
| 2 | 1 | wtr 2754 | . 2 wff Tr A |
| 3 | 1 | cuni 2569 | . . 3 class ∪A |
| 4 | 3, 1 | wss 2099 | . 2 wff ∪A ⊆ A |
| 5 | 2, 4 | wb 144 | 1 wff (Tr A ↔ ∪A ⊆ A) |
| Colors of variables: wff set class |
| This definition is referenced by: dftr2 2756 dftr4 2759 treq 2760 trv 2766 unisuc 3049 orduniss 3066 onuninsuci 3194 trcl 4791 |