lean2/tests/lean/run/coercion_bug2.lean

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import data.nat
open nat
inductive list (T : Type) : Type :=
nil {} : list T,
cons : T → list T → list T
definition length {T : Type} : list T → nat := list.rec 0 (fun x l m, succ m)
theorem length_nil {T : Type} : length (@nil T) = 0
:= refl _