mathlib documentation

data.list.sections

theorem list.mem_sections {α : Type u} {L : list (list α)} {f : list α} :

f ∈ L.sections ↔ list.forall₂ has_mem.mem f L

theorem list.mem_sections_length {α : Type u} {L : list (list α)} {f : list α} (h : f ∈ L.sections) :

f.length = L.length

theorem list.rel_sections {α : Type u} {β : Type v} {r : α → β → Prop} :

(list.forall₂ (list.forall₂ r) ⇒ list.forall₂ (list.forall₂ r)) list.sections list.sections