Metamath Proof Explorer
Description: A relation composed once is itself. (Contributed by Drahflow, 12-Nov-2015) (Revised by RP, 30-May-2020) (Revised by AV, 12-Jul-2024)
|
|
Ref |
Expression |
|
Hypothesis |
relexp1d.1 |
⊢ ( 𝜑 → 𝑅 ∈ 𝑉 ) |
|
Assertion |
relexp1d |
⊢ ( 𝜑 → ( 𝑅 ↑𝑟 1 ) = 𝑅 ) |
Proof
Step |
Hyp |
Ref |
Expression |
1 |
|
relexp1d.1 |
⊢ ( 𝜑 → 𝑅 ∈ 𝑉 ) |
2 |
|
relexp1g |
⊢ ( 𝑅 ∈ 𝑉 → ( 𝑅 ↑𝑟 1 ) = 𝑅 ) |
3 |
1 2
|
syl |
⊢ ( 𝜑 → ( 𝑅 ↑𝑟 1 ) = 𝑅 ) |