Hi Martin, On 11/05/2021 09:11, Martin Desharnais wrote:
Dear Isabelle developers,I noticed that the map_ran function from HOL-Library is defined with the following type annotation.definition map_ran :: "('key ⇒ 'val ⇒ 'val) ⇒ ('key × 'val) list ⇒ ('key × 'val) list"where "map_ran f = map (λ(k, v). (k, f k v))"
Somebody wasn't thinking when they fixed that type. I have generalized it as you suggested and everything still works, as expected.
This means that it is not possible to use map_ran to map an association list
from one range type to another. This would be possible if it had the following
type annotation (or no type annotation at all).
('key ⇒ 'val1 ⇒ 'val2) ⇒ ('key × 'val1) list ⇒ ('key × 'val2) list
While I am at it, I also have the following two small lemmas that I found useful and would like to add to HOL-Library.AList. Note that map_ran_Cons is only a generalization of map_ran_simps(2) that avoids the need for a case analysis of the product x. Is there any objection?lemma map_fst_map_ran[simp]: "map fst (map_ran f xs) = map fst xs" by (simp add: map_ran_def case_prod_beta)lemma map_ran_Cons: "map_ran f (x # xs) = (fst x, f (fst x) (snd x)) # map_ran f xs"by (simp add: map_ran_def case_prod_beta)
No objections. Tobias
Regards, Martin Desharnais _______________________________________________ isabelle-dev mailing list [email protected] https://mailman46.in.tum.de/mailman/listinfo/isabelle-dev
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