| ⊢ | f∗≡empty ∨ (f ∧more) ; f∗ | CSEqv | 
Proof:
| 1 | ⊢ f+ ≡ f ∨ (f ∧more) ; f+                                       | |
| 2  | ⊢ empty ≡¬more                                                         | |
| 3  | ⊢ empty ∨ f+ ≡empty ∨ (f ∧more) ∨ (f ∧more) ; f+ | |
| 4  | ⊢ (f ∧more) ; empty ≡ f ∧more                                  | |
| 5  | ⊢ (f ∧more) ; (empty ∨ f+) ≡             | |
| (f ∧more) ; empty ∨ (f ∧more) ; f+                               | ||
| 6  | ⊢ empty ∨ f+ ≡empty ∨ ((f ∧more) ; (empty ∨ f+))   | |
| 7  | ⊢ f∗≡empty ∨ (f ∧more) ; f∗               | 6, def. of ∗   | 
qed