5 lines
137 B
Text
5 lines
137 B
Text
|
example (A B C D : Prop) (h1 : A → B) (h2 : B → C) (h3 : C → D) : A → D :=
|
||
|
|
calc A → B : h1
|
||
|
|
... → C : h2
|
||
|
|
... → D : h3
|