Nuprl - Proof: l before-iff 2 1 1 2

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1. T: Type
2. L: T List
3. u: T
4. v: T List
5. x,y:T. x before y v (L1,L2,L3:T List. v = (L1 @ [x] @ L2 @ [y] @ L3))
6. x: T
7. y: T
8. x before y v

L1,L2,L3:T List. [u / v] = (L1 @ [x] @ L2 @ [y] @ L3)

By: InstHyp [x;y] -4 THEN ThinTrivial THEN Analyze -1 THEN InstConcl [[u / L1]]

Generated subgoal:

1 9. x before y v (L1,L2,L3:T List. v = (L1 @ [x] @ L2 @ [y] @ L3))
10. L1: T List
11. L2,L3:T List. v = (L1 @ [x] @ L2 @ [y] @ L3)
L2,L3:T List. [u / v] = ([u / L1] @ [x] @ L2 @ [y] @ L3) 2 steps

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(14steps total) PrintForm Definitions Lemmas graph 1 1 Sections Graphs Doc