19 lines
506 B
Text
19 lines
506 B
Text
open tactic nat expr option
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definition succ_eq_add [defeq] (n : nat) : succ n = n + 1 :=
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rfl
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example (a b : nat) : a = b → succ (succ a) = succ (b + 1) :=
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by do intro `Heq,
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t ← target,
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trace_state,
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t' ← defeq_simp t,
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change t',
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trace "---- after change ----",
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trace_state,
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get_local `a >>= subst,
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t ← target,
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match is_eq t with
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| some (lhs, rhs) := do pr ← mk_app `eq.refl [lhs], exact pr
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| none := failed
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end
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