2015-03-07 00:48:48 +00:00
|
|
|
example (a b c : Prop) : a ∧ b ↔ b ∧ a :=
|
|
|
|
begin
|
|
|
|
apply iff.intro,
|
|
|
|
{intro H,
|
|
|
|
match H with
|
2015-05-03 00:32:03 +00:00
|
|
|
| and.intro H₁ H₂ := by apply and.intro; repeat assumption
|
2015-03-07 00:48:48 +00:00
|
|
|
end},
|
|
|
|
{intro H,
|
|
|
|
match H with
|
2015-05-03 00:32:03 +00:00
|
|
|
| and.intro H₁ H₂ := by apply and.intro; repeat assumption
|
2015-03-07 00:48:48 +00:00
|
|
|
end},
|
|
|
|
end
|