`contains`

definition

show as: view math explainer →

module: IndisputableMonolith.Ethics.StakeGraph
domain: Ethics
line: 15 · github
papers citing: none yet

open explainer

Generate a durable explainer page for this declaration.

open lean source

IndisputableMonolith.Ethics.StakeGraph on GitHub at line 15.

browse module

All declarations in this module, on Recognition.

explainer page

Tracked in the explainer inventory; generation is lazy so crawlers do not trigger LLM jobs.

open explainer

depends on

used by

formal source

  12
  13namespace StakeGraph
  14
  15def contains (xs : List Stakeholder) (s : Stakeholder) : Bool :=
  16  xs.any (fun x => decide (x = s))
  17
  18def neighbors (G : StakeGraph) (nodes : List Stakeholder) (s : Stakeholder) : List Stakeholder :=
  19  nodes.filter (fun t => G.edge s t)
  20
  21def reachable (G : StakeGraph) (nodes : List Stakeholder) (src dst : Stakeholder) : Bool :=
  22  let rec dfs (front : List Stakeholder) (visited : List Stakeholder) : Bool :=
  23    match front with
  24    | [] => False
  25    | v :: vs =>
  26        if decide (v = dst) then True else
  27        let nbrs := neighbors G nodes v
  28        let fresh := nbrs.filter (fun w => ¬ contains visited w)
  29        dfs (vs ++ fresh) (v :: visited)
  30  dfs [src] []
  31
  32def mutualReachable (G : StakeGraph) (nodes : List Stakeholder) (s t : Stakeholder) : Bool :=
  33  reachable G nodes s t && reachable G nodes t s
  34
  35def hasCycle (G : StakeGraph) (nodes : List Stakeholder) : Bool :=
  36  nodes.any (fun s => G.edge s s)
  37  || nodes.any (fun s =>
  38        nodes.any (fun t => (¬ decide (s = t)) && mutualReachable G nodes s t))
  39
  40end StakeGraph
  41end Ethics
  42end IndisputableMonolith
  43

papers checked against this theorem

No papers in the current corpus map onto this theorem yet.