[Merged by Bors] - feat(data/option/basic): option.map is injective
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* prove that `option.map : (α → β) → (option α → option β)` is injective; * add `iff` version of this lemma; * add `option.map_comp_some` and `option.map_eq_id`; * drop `option.map_id'`: it was the same as `option.map_id`.
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src/data/option/basic.lean
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| /-- `option.map` is an injective function. -/ | ||
| theorem map_injective' : function.injective (@option.map α β) := | ||
| λ f g h, funext $ λ x, some_injective _ $ by simp only [← map_some', h] |
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How is this different from the unprimed version?
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The unprimed version says that option.map f is injective whenever f is injective. Should I rename it to function.injective.option_map?
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I think it's fine as is, I just misread the docstring
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Co-authored-by: Eric Wieser <wieser.eric@gmail.com>
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Co-authored-by: Eric Wieser <wieser.eric@gmail.com>
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* prove that `option.map : (α → β) → (option α → option β)` is injective; * add `iff` version of this lemma; * add `option.map_comp_some` and `option.map_eq_id`; * drop `option.map_id'`: it was the same as `option.map_id`.
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Pull request successfully merged into master. Build succeeded: |
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option.map is injectiveoption.map is injective
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option.map : (α → β) → (option α → option β)is injective;iffversion of this lemma;option.map_comp_someandoption.map_eq_id;option.map_id': it was the same asoption.map_id.