2d78387541
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
12 lines
264 B
Text
12 lines
264 B
Text
import logic
|
||
using tactic
|
||
|
||
theorem tst (a b : Prop) (H : ¬ a ∨ ¬ b) (Hb : b) : ¬ a ∧ b :=
|
||
begin
|
||
apply and_intro,
|
||
apply not_intro,
|
||
assume Ha, or_elim H
|
||
(assume Hna, @absurd _ false Ha Hna)
|
||
(assume Hnb, @absurd _ false Hb Hnb),
|
||
assumption
|
||
end
|