| ⊢ | (f ∧fin w) ; g ≡ f ; (w ∧ g) | AndFinChopEqvStateAndChop | 
Proof for  ⊃ :
| 1  | ⊢ (fin w)  w                                                 | |
| 2  | ⊢ f ∧fin w ⊃fin w                                         | |
| 3  | ⊢ (fin w)  w ⊃ (f ∧fin w)  w                               | |
| 4  | ⊢ (f ∧fin w)  w                                            | |
| 5  | ⊢ (f ∧fin w) ; g ∧ (f ∧fin w)  w ⊃ (f ∧fin w) ; (g ∧ w) | |
| 6  | ⊢ (f ∧fin w) ; g ⊃ (f ∧fin w) ; (g ∧ w)                      | |
| 7  | ⊢ (f ∧fin w) ; (g ∧ w) ⊃ f ; (g ∧ w)                          | |
| 8  | ⊢ g ∧ w ⊃ w ∧ g                                           | |
| 9  | ⊢ f ; (g ∧ w) ⊃ f ; (w ∧ g)                                      | |
| 10 | ⊢ (f ∧fin w) ; g ⊃ f ; (w ∧ g)                                  | 
qed
Proof of ⊂:
| 1 | ⊢ f ⊃ (f ∧fin w) ∨fin ¬w                       | |
| 2  | ⊢ f ; (w ∧ g) ⊃ ((f ∧fin w) ∨fin ¬w) ; (w ∧ g) | |
| 3  | ⊢ ((f ∧fin w) ∨fin ¬w) ; (w ∧ g) ≡       | |
| (f ∧fin w) ; (w ∧ g) ∨ (fin ¬w) ; (w ∧ g)            | ||
| 4  | ⊢ (fin ¬w) ; (w ∧ g) ⊃ (¬w ∧ (w ∧ g))            | |
| 5  | ⊢ ¬ (¬w ∧ (w ∧ g))                                   | |
| 6  | ⊢ f ; (w ∧ g) ⊃ (f ∧fin w) ; (w ∧ g)               | |
| 7  | ⊢ (f ∧fin w) ; (w ∧ g) ⊃ (f ∧fin w) ; g          | |
| 8  | ⊢ f ; (w ∧ g) ⊃ (f ∧fin w) ; g                    | 
qed