lean2/tests/lean/run/eqn_tac.lean

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Text

open nat
definition foo : nat → nat
| foo zero := begin exact zero end
| foo (succ a) := begin exact a end
example : foo zero = zero := rfl
example (a : nat) : foo (succ a) = a := rfl
definition bla : nat → nat
| bla zero := zero
| bla (succ a) :=
begin
apply foo,
exact a
end
example (a : nat) : foo (succ a) = bla (succ (succ a)) := rfl