lean4-htt/tests/lean/unfold_crash.lean
2016-07-29 13:03:23 -07:00

10 lines
211 B
Text

import data.nat
open nat tactic
example (a b : nat) : a = succ b → a = b + 1 :=
by do
H ← intro `H,
try (unfold_at [`nat.succ] H),
unfold [`add], dsimp, unfold [`nat.add],
trace_state,
assumption