lean4-htt/tests/lean/revertlet.lean
2021-05-20 15:17:36 -07:00

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Text

theorem ex (n : Nat) (h : n = 0) : 0 + n = 0 := by
let m := n + 1
let v := m + 1
have : v = n + 2 := rfl
traceState
subst h
traceState
rfl