lean2/library/standard/option.lean
Leonardo de Moura e1d807a077 feat(library/standard): add inhabited, and files option and unit
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2014-06-29 19:30:38 -07:00

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import logic
inductive option (A : Type) : Type :=
| none {} : option A
| some : A → option A
theorem inhabited_option (A : Type) : inhabited (option A)
:= inhabited_intro none