example (a b c : Prop) : a ∧ b ∧ c ↔ c ∧ b ∧ a := by simp example (a b c : Prop) : a ∧ false ∧ c ↔ false := by simp example (a b c : Prop) : a ∨ false ∨ b ↔ b ∨ a := by simp example (a b c : Prop) : ¬ true ∨ false ∨ b ↔ b := by simp example (a b c : Prop) : if true then a else b ↔ if false then b else a := by simp example (a b : Prop) : a ∧ not a ↔ false := by simp