{
  inputs,
  tree,
  systems,
}: let
  nixlib = inputs.nixpkgs.lib;
  inherit (nixlib.modules) mkOrder mkOverride defaultOverridePriority;
  inherit (nixlib.strings) splitString toLower;
  inherit (nixlib.lists) imap0 elemAt findFirst;
  inherit (nixlib.attrsets) mapAttrs listToAttrs nameValuePair;
  inherit (nixlib.strings) hasPrefix hasInfix substring fixedWidthString replaceStrings concatMapStringsSep;
  inherit (nixlib.trivial) flip toHexString bitOr;

  toHexStringLower = v: toLower (toHexString v);

  hexCharToInt = let
    hexChars = ["0" "1" "2" "3" "4" "5" "6" "7" "8" "9" "a" "b" "c" "d" "e" "f"];
    pairs = imap0 (flip nameValuePair) hexChars;
    idx = listToAttrs pairs;
  in
    char: idx.${char};

  eui64 = mac: let
    parts = map toLower (splitString ":" mac);
    part = elemAt parts;
    part0 = part: let
      nibble1' = hexCharToInt (substring 1 1 part);
      nibble1 = bitOr 2 nibble1';
      nibble0 = substring 0 1 part;
    in
      nibble0 + (fixedWidthString 1 "0" (toHexStringLower nibble1));
  in "${part0 (part 0)}${part 1}:${part 2}ff:fe${part 3}:${part 4}${part 5}";

  userIs = group: user: builtins.elem group (user.extraGroups ++ [user.group]);

  mkWinPath = replaceStrings ["/"] ["\\"];
  mkBaseDn = domain: concatMapStringsSep "," (part: "dc=${part}") (splitString "." domain);
  mkAddress6 = addr: if hasInfix ":" addr && ! hasPrefix "[" addr then "[${addr}]" else addr;

  coalesce = findFirst (v: v != null) null;
  mapListToAttrs = f: l: listToAttrs (map f l);

  overrideOptionDefault = 1500;
  overrideAlmostOptionDefault = 1400;
  overrideDefault = 1000;
  overrideAlmostDefault = 900;
  overrideNone = defaultOverridePriority; # 100
  overrideAlmostForce = 75;
  overrideForce = 50;
  overrideVM = 10;
  mkAlmostOptionDefault = mkOverride overrideAlmostOptionDefault;
  mkAlmostDefault = mkOverride overrideAlmostDefault;
  mkAlmostForce = mkOverride overrideAlmostForce;
  orderBefore = 500;
  orderNone = 1000;
  orderAfter = 1500;
  orderAlmostAfter = 1400;
  mkAlmostAfter = mkOrder 1400;
  mapOverride = priority: mapAttrs (_: mkOverride priority);
  mapOptionDefaults = mapOverride overrideOptionDefault;
  mapAlmostOptionDefaults = mapOverride overrideAlmostOptionDefault;
  mapDefaults = mapOverride overrideDefault;

  treeToModulesOutput = modules:
    {
      ${
        if modules ? __functor
        then "default"
        else null
      } =
        modules.__functor modules;
    }
    // builtins.removeAttrs modules ["__functor"];
in {
  inherit tree nixlib inputs systems;
  meta = tree.impure;
  std = inputs.self.lib.Std.Std.compat;
  Std = inputs.std-fl.lib;
  lib = {
    domain = "gensokyo.zone";
    inherit treeToModulesOutput userIs
      eui64 mkWinPath mkBaseDn mkAddress6
      toHexStringLower hexCharToInt
      mapListToAttrs coalesce
      mkAlmostOptionDefault mkAlmostDefault mkAlmostForce  mapOverride mapOptionDefaults mapAlmostOptionDefaults mapDefaults
      overrideOptionDefault overrideAlmostOptionDefault overrideDefault overrideAlmostDefault overrideNone overrideAlmostForce overrideForce overrideVM
      orderBefore orderNone orderAfter orderAlmostAfter
      mkAlmostAfter;
    inherit (inputs.arcexprs.lib) unmerged json;
  };
  gensokyo-zone = {
    inherit inputs;
    inherit (inputs) self;
    inherit (inputs.self) overlays;
    inherit (inputs.self.lib) tree meta lib systems;
  };
  generate = import ./generate.nix {inherit inputs tree;};
}