10 lines
283 B
Text
10 lines
283 B
Text
|
example (p q r : Prop) : p ∧ q ∧ r → q ∧ p :=
|
||
|
|
assume Hpqr : p ∧ q ∧ r,
|
||
|
|
have Hp : p, from and.elim_left Hpqr,
|
||
|
|
have Hqr : q ∧ r, from and.elim_right Hpqr,
|
||
|
|
have Hq : q, from and.elim_left Hqr,
|
||
|
|
show q ∧ p, using Hp Hq, from
|
||
|
|
proof
|
||
|
|
and.intro Hq Hp
|
||
|
|
qed
|