List.map_take_sym: law of bend-mathlib@0.8.1.0 Import: import bend-mathlib@0.8.1.0/list.bend as List Lines 2623-2630 of bend-mathlib@0.8.1.0/list.bend: https://jend.leeeet.dev/read.txt?path=bend-mathlib@0.8.1.0/list.bend&start_line=2623&end_line=2630 import Base # Mapping commutes with taking: map f (take n xs) = take n (map f xs), reversed to rewrite toward the simple side. law map_take_sym: for ~A: Type for ~B: Type for ~f: A -> B for xs: List for n: Nat {List.take(&1, B, List.map(~A, ~B, ~f, xs), n) == List.map(~A, ~B, ~f, List.take(&1, A, xs, n)) : List} Uses (6): https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Equal.sym https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List.map https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List.take https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat https://jend.leeeet.dev/definition.txt?path=bend-mathlib@0.8.1.0/list.bend&name=map_take