rfl
case mpr.mk.mk.refl
α : Type u
n : Nat
inst✝ : DecidableEq α
x : SizedArray α n
i : Nat
hi hj : i < Array.size x.val
hxij : x.val[↑{ val := i, isLt := hi }] = x.val[↑{ val := i, isLt := hj }]
⊢ { val := i, isLt := hi } = { val := i, isLt := hj }
no goals