Description: Define the class of all fixpoints of a relationship. (Contributed by Scott Fenton, 11-Apr-2012)
Ref | Expression | ||
---|---|---|---|
Assertion | df-fix | ⊢ Fix 𝐴 = dom ( 𝐴 ∩ I ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
0 | cA | ⊢ 𝐴 | |
1 | 0 | cfix | ⊢ Fix 𝐴 |
2 | cid | ⊢ I | |
3 | 0 2 | cin | ⊢ ( 𝐴 ∩ I ) |
4 | 3 | cdm | ⊢ dom ( 𝐴 ∩ I ) |
5 | 1 4 | wceq | ⊢ Fix 𝐴 = dom ( 𝐴 ∩ I ) |