Description: For sets, being an element of the class of symmetric relations ( df-symrels ) is equivalent to satisfying the symmetric relation predicate. (Contributed by Peter Mazsa, 17-Aug-2021)
Ref | Expression | ||
---|---|---|---|
Assertion | elsymrelsrel | ⊢ ( 𝑅 ∈ 𝑉 → ( 𝑅 ∈ SymRels ↔ SymRel 𝑅 ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | elrelsrel | ⊢ ( 𝑅 ∈ 𝑉 → ( 𝑅 ∈ Rels ↔ Rel 𝑅 ) ) | |
2 | 1 | anbi2d | ⊢ ( 𝑅 ∈ 𝑉 → ( ( ◡ 𝑅 ⊆ 𝑅 ∧ 𝑅 ∈ Rels ) ↔ ( ◡ 𝑅 ⊆ 𝑅 ∧ Rel 𝑅 ) ) ) |
3 | elsymrels2 | ⊢ ( 𝑅 ∈ SymRels ↔ ( ◡ 𝑅 ⊆ 𝑅 ∧ 𝑅 ∈ Rels ) ) | |
4 | dfsymrel2 | ⊢ ( SymRel 𝑅 ↔ ( ◡ 𝑅 ⊆ 𝑅 ∧ Rel 𝑅 ) ) | |
5 | 2 3 4 | 3bitr4g | ⊢ ( 𝑅 ∈ 𝑉 → ( 𝑅 ∈ SymRels ↔ SymRel 𝑅 ) ) |