Answers to selected exercises

Exercise 1 We may take ⌉ and ∧ as primitive, and consider ⍺ ⋁ β as an abbreviation for ⌉ (⌉⍺ ∧⌉ β). We may also take ⌉ and ⋁ as primitive, and regard ⍺ A β as an abbreviation for ⌉ (⌉⍺ ⋁⌉ β).