You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
35 lines
392 B
Plaintext
35 lines
392 B
Plaintext
2 years ago
|
import NNG.Metadata
|
||
|
|
import NNG.MyNat.Addition
|
||
|
|
import Std.Tactic.RCases
|
||
|
|
|
||
|
|
Game "NNG"
|
||
|
|
World "AdvProposition"
|
||
|
|
Level 5
|
||
|
|
Title ""
|
||
|
|
|
||
|
|
open MyNat
|
||
|
|
|
||
|
|
Introduction
|
||
|
|
"
|
||
|
|
|
||
|
|
"
|
||
|
|
|
||
|
|
Statement iff_trans
|
||
|
|
""
|
||
|
|
(P Q R : Prop) : (P ↔ Q) → (Q ↔ R) → (P ↔ R) := by
|
||
|
|
intro hpq hqr
|
||
|
|
constructor
|
||
|
|
intro p
|
||
|
|
apply hqr.1
|
||
|
|
apply hpq.1
|
||
|
|
assumption
|
||
|
|
intro r
|
||
|
|
apply hpq.2
|
||
|
|
apply hqr.2
|
||
|
|
assumption
|
||
|
|
|
||
|
|
Conclusion
|
||
|
|
"
|
||
|
|
|
||
|
|
"
|