Nuprl - Proof: swap adjacent instance 2 2 1 1

IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html
At: swap adjacent instance 2 2 1 1

1. A : Type
2. P : A

Prop
3. X : A List
4. Y : A List
5. a : A
6. b : A
7. P(a,b)
8. i :

9. i<||X @ [b; a / Y]||
10. i<||X||

(X @ [b; a / Y])[i] = (X @ [a; b / Y])[((||X||, ||X||+1)(i))]

By:	Subst' ((\|\|X\|\|, \|\|X\|\|+1)(i) = i) 0 THEN Try (Unfold `flip` 0 THEN Reduce 0 THEN Repeat SplitOnConclITE)

Generated subgoal:

1 (X @ [b; a / Y])[i] = (X @ [a; b / Y])[i]
1 step

About:

IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html