cases hi
case succ.refine_1.inl
n : Nat
x : Permutation n
iv : Inversion x
i j : Fin n
hlt : i < j
hinv : x[↑i] > x[↑j]
k : Nat
hk : k < n
invs : Array (Inversion x)
IH : ↑j < k → { fst := i, snd := j, lt := hlt, inverted := hinv } ∈ invs
hjk : ↑j < k + 1
this : ↑i < k
hi : ↑i < 0
⊢ { fst := i, snd := j, lt := hlt, inverted := hinv } ∈ invs
no goals