FBoxImpDiamondImpDiamond

⊢ (f ⊃ g) ⊃ f ⊃ g FBoxImpDiamondImpDiamond

Proof:

1
(f ⊃ g) ⊃ ⟨skip∗⟩f ⊃ ⟨skip∗⟩g
2
f ≡⟨skip∗⟩f
3
g ≡⟨skip∗⟩g
4
(f ⊃ g) ⊃ f ⊃ g
2, 3,Prop

qed

The following slightly obscure theorem is used in the proof of FBoxImpDist:

2024-08-03
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