Description: Alternate definition of the class of symmetric relations. (Contributed by Peter Mazsa, 22-Jul-2021)
Ref | Expression | ||
---|---|---|---|
Assertion | dfsymrels5 | ⊢ SymRels = { 𝑟 ∈ Rels ∣ ∀ 𝑥 ∀ 𝑦 ( 𝑥 𝑟 𝑦 ↔ 𝑦 𝑟 𝑥 ) } |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | dfsymrels4 | ⊢ SymRels = { 𝑟 ∈ Rels ∣ ◡ 𝑟 = 𝑟 } | |
2 | elrelscnveq2 | ⊢ ( 𝑟 ∈ Rels → ( ◡ 𝑟 = 𝑟 ↔ ∀ 𝑥 ∀ 𝑦 ( 𝑥 𝑟 𝑦 ↔ 𝑦 𝑟 𝑥 ) ) ) | |
3 | 1 2 | rabimbieq | ⊢ SymRels = { 𝑟 ∈ Rels ∣ ∀ 𝑥 ∀ 𝑦 ( 𝑥 𝑟 𝑦 ↔ 𝑦 𝑟 𝑥 ) } |