| ⊢ (skip ⊃ f) ∧ g ⊃ (skip ∧ f) ⌢ g | BfSkipImpAndNextImpAndSkipAndChop | 
Proof:
| 1 |  (skip  ⊃ f) ∧ (skip ⌢ g)  ⊃ ((skip  ⊃ f) ∧skip) ⌢ g | |
| 2  | (skip  ⊃ f) ∧skip  ⊃ skip ∧ f                          | |
| 3  | ((skip  ⊃ f) ∧skip) ⌢ g  ⊃ (skip ∧ f) ⌢ g            | |
| 4  |  (skip  ⊃ f) ∧ (skip ⌢ g)  ⊃ (skip ∧ f) ⌢ g           | |
| 5  |  (skip  ⊃ f) ∧ g  ⊃ (skip ∧ f) ⌢ g                    | 4, def. of              | 
qed