diff --git a/2015/src/main/scala/aoc2015/Day03.scala b/2015/src/main/scala/aoc2015/Day03.scala
index 09775cae..f3d51807 100644
--- a/2015/src/main/scala/aoc2015/Day03.scala
+++ b/2015/src/main/scala/aoc2015/Day03.scala
@@ -1,7 +1,7 @@
 package aoc2015
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 object Day03 extends AoC:
 
diff --git a/2015/src/main/scala/aoc2015/Day11.scala b/2015/src/main/scala/aoc2015/Day11.scala
index f0e22233..4afdc25f 100644
--- a/2015/src/main/scala/aoc2015/Day11.scala
+++ b/2015/src/main/scala/aoc2015/Day11.scala
@@ -31,6 +31,8 @@ object Day11 extends AoC:
       case Zero extends Carry(0x00)
       case One  extends Carry(value = 0x01)
 
+    given CanEqual[Carry, Carry] = CanEqual.derived
+    
     val MinValue: Char   = 'a'
     val MaxValue: Char   = 'z'
     val ValueRange: Char = (MaxValue - MinValue + 1).toChar
diff --git a/2015/src/main/scala/aoc2015/Day12.scala b/2015/src/main/scala/aoc2015/Day12.scala
index da7a2ff1..69b8c1c0 100644
--- a/2015/src/main/scala/aoc2015/Day12.scala
+++ b/2015/src/main/scala/aoc2015/Day12.scala
@@ -39,6 +39,8 @@ object Day12 extends AoC:
   case class Num(underlying: Long)             extends Json
   case class Arr(underlying: List[Json])       extends Json
   case class Obj(underlying: Map[String,Json]) extends Json
+  
+  given CanEqual[Json, Json] = CanEqual.derived
 
   def solve(json: Json, objValueFilter: Json => Boolean = _ => true): Long =
     def loop(acc: Long, json: Json): Long =
diff --git a/2015/src/main/scala/aoc2015/Day21.scala b/2015/src/main/scala/aoc2015/Day21.scala
index 759b86f2..2c434799 100644
--- a/2015/src/main/scala/aoc2015/Day21.scala
+++ b/2015/src/main/scala/aoc2015/Day21.scala
@@ -9,7 +9,7 @@ object Day21 extends AoC:
   object Player:
     def equip(points: Int, weapon: Weapon, armor: Option[Armor], rings: Seq[Ring]): Player =
       assert(rings.size <= 2, "max 2 rings")
-      assert(rings == rings.distinct, "max one of a kind")
+      assert((rings diff rings.distinct).isEmpty, "max one of a kind")
       Player( points = points
             , damage = weapon.damage + rings.map(_.damage).sum
             , armor  = armor.map(_.armor).getOrElse(0) + rings.map(_.armor).sum
@@ -41,6 +41,8 @@ object Day21 extends AoC:
   enum Outcome:
     case Won
     case Lost
+    
+  given CanEqual[Outcome, Outcome] = CanEqual.derived    
 
   case class Game(player: Player, boss: Player):
     import Outcome.*
@@ -67,7 +69,7 @@ object Day21 extends AoC:
       w  <- Weapon.values.toList
       a  <- Armor.values.toList.map(Option(_)) :+ Option.empty[Armor]
       rs <- Ring.values.toList.map(List(_)) ++ Ring.values.toList.combinations(2) ++ List(List.empty[Ring])
-      if rs == rs.distinct
+      if (rs diff rs.distinct).isEmpty
     yield
       Player.equip(100, w, a, rs)
 
diff --git a/2015/src/main/scala/aoc2015/Day22.scala b/2015/src/main/scala/aoc2015/Day22.scala
index 4ff1fbd9..91d642ae 100644
--- a/2015/src/main/scala/aoc2015/Day22.scala
+++ b/2015/src/main/scala/aoc2015/Day22.scala
@@ -12,6 +12,8 @@ object Day22 extends AoC:
     case Recharge     extends Spell(229, 5)
 
   import Spell.*
+  
+  given CanEqual[Spell, Spell] = CanEqual.derived
 
   val Spells = Set(MagicMissile, Drain, Shield, Poison, Recharge)
 
diff --git a/2016/src/main/scala/aoc2016/Day01.scala b/2016/src/main/scala/aoc2016/Day01.scala
index 75c80eef..41016071 100644
--- a/2016/src/main/scala/aoc2016/Day01.scala
+++ b/2016/src/main/scala/aoc2016/Day01.scala
@@ -1,7 +1,7 @@
 package aoc2016
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 import scala.annotation.tailrec
 import scala.util.Try
 
diff --git a/2016/src/main/scala/aoc2016/Day10.scala b/2016/src/main/scala/aoc2016/Day10.scala
index ce8b32b5..62061382 100644
--- a/2016/src/main/scala/aoc2016/Day10.scala
+++ b/2016/src/main/scala/aoc2016/Day10.scala
@@ -1,6 +1,8 @@
 package aoc2016
 
 import nmcb.*
+
+import scala.CanEqual.derived
 import scala.collection.mutable
 
 object Day10 extends AoC:
@@ -10,6 +12,8 @@ object Day10 extends AoC:
     case Out(override val index: Int) extends Target(index)
 
   import Target.*
+  
+  given CanEqual[Target, Target] = CanEqual.derived
 
   enum Inst:
     case Init(bot: Bot, value: Int)
diff --git a/2016/src/main/scala/aoc2016/Day13.scala b/2016/src/main/scala/aoc2016/Day13.scala
index 573e0ec6..ebac03db 100644
--- a/2016/src/main/scala/aoc2016/Day13.scala
+++ b/2016/src/main/scala/aoc2016/Day13.scala
@@ -1,7 +1,7 @@
 package aoc2016
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 import scala.collection.*
 import scala.collection.immutable.Map
diff --git a/2016/src/main/scala/aoc2016/Day17.scala b/2016/src/main/scala/aoc2016/Day17.scala
index 82f946f8..c7529491 100644
--- a/2016/src/main/scala/aoc2016/Day17.scala
+++ b/2016/src/main/scala/aoc2016/Day17.scala
@@ -2,7 +2,7 @@ package aoc2016
 
 import nmcb.*
 import nmcb.predef.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 import java.security.MessageDigest
 import scala.collection.*
diff --git a/2016/src/main/scala/aoc2016/Day22.scala b/2016/src/main/scala/aoc2016/Day22.scala
index 0148c4ec..aca040c6 100644
--- a/2016/src/main/scala/aoc2016/Day22.scala
+++ b/2016/src/main/scala/aoc2016/Day22.scala
@@ -1,7 +1,7 @@
 package aoc2016
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 object Day22 extends AoC:
 
@@ -16,6 +16,8 @@ object Day22 extends AoC:
       else if isMassive then '#'
       else                   '.'
 
+  given CanEqual[Node, Node] = CanEqual.derived
+  
   val nodes: Map[Pos,Node] =
     lines
       .filter(_.startsWith("/dev/grid/node"))
@@ -24,7 +26,7 @@ object Day22 extends AoC:
         Pos.of(x, y) -> Node(used, avail)
       .toMap
 
-  def viable(nodes: Map[Pos,Node]): Vector[(Node,Node)] =
+  def viable(nodes: Map[Pos, Node]): Vector[(Node, Node)] =
     for
       (_,a) <- nodes.toVector
       (_,b) <- nodes.toVector
diff --git a/2016/src/main/scala/aoc2016/Day24.scala b/2016/src/main/scala/aoc2016/Day24.scala
index f29827cf..156be145 100644
--- a/2016/src/main/scala/aoc2016/Day24.scala
+++ b/2016/src/main/scala/aoc2016/Day24.scala
@@ -1,7 +1,7 @@
 package aoc2016
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 object Day24 extends AoC:
 
diff --git a/2017/src/main/scala/aoc2017/Day03.scala b/2017/src/main/scala/aoc2017/Day03.scala
index 5a6bc2b2..74ebe47d 100644
--- a/2017/src/main/scala/aoc2017/Day03.scala
+++ b/2017/src/main/scala/aoc2017/Day03.scala
@@ -1,7 +1,7 @@
 package aoc2017
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 import nmcb.predef.*
 
 import scala.annotation.tailrec
diff --git a/2017/src/main/scala/aoc2017/Day06.scala b/2017/src/main/scala/aoc2017/Day06.scala
index 8c08a37c..c5e7ab50 100644
--- a/2017/src/main/scala/aoc2017/Day06.scala
+++ b/2017/src/main/scala/aoc2017/Day06.scala
@@ -41,6 +41,8 @@ object Day06 extends AoC:
           loop(next, seen :+ current)
       loop(this)
 
+  given CanEqual[Area, Area] = CanEqual.derived
+  
   override lazy val answer1: Int =
     Area(banks).redistribute.size - 1
 
diff --git a/2017/src/main/scala/aoc2017/Day11.scala b/2017/src/main/scala/aoc2017/Day11.scala
index 1eedf295..c180fa34 100644
--- a/2017/src/main/scala/aoc2017/Day11.scala
+++ b/2017/src/main/scala/aoc2017/Day11.scala
@@ -14,6 +14,8 @@ object Day11 extends AoC:
     case NW
 
   import Dir.*
+  
+  given CanEqual[Dir, Dir] = CanEqual.derived
 
   case class Hex(x: Int, y: Int, z: Int):
     assert(x + y + z == 0)
diff --git a/2017/src/main/scala/aoc2017/Day14.scala b/2017/src/main/scala/aoc2017/Day14.scala
index efd37062..d671803b 100644
--- a/2017/src/main/scala/aoc2017/Day14.scala
+++ b/2017/src/main/scala/aoc2017/Day14.scala
@@ -1,7 +1,7 @@
 package aoc2017
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 import Day10.KnotHash
 import Day12.Dijkstra
diff --git a/2017/src/main/scala/aoc2017/Day19.scala b/2017/src/main/scala/aoc2017/Day19.scala
index 5102957b..b91e8de1 100644
--- a/2017/src/main/scala/aoc2017/Day19.scala
+++ b/2017/src/main/scala/aoc2017/Day19.scala
@@ -1,7 +1,7 @@
 package aoc2017
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 import scala.annotation.tailrec
 
diff --git a/2017/src/main/scala/aoc2017/Day22.scala b/2017/src/main/scala/aoc2017/Day22.scala
index 70ae85b9..a43a1d11 100644
--- a/2017/src/main/scala/aoc2017/Day22.scala
+++ b/2017/src/main/scala/aoc2017/Day22.scala
@@ -1,7 +1,7 @@
 package aoc2017
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 import nmcb.predef.*
 
 object Day22 extends AoC:
@@ -10,6 +10,8 @@ object Day22 extends AoC:
     case Clean, Infected, Weakened, Flagged
 
   import Status.*
+  
+  given CanEqual[Status, Status] = CanEqual.derived
 
   case class Carrier(nodes: Map[Pos,Status], current: Pos, dir: Dir, infected: Int = 0):
 
diff --git a/2017/src/main/scala/aoc2017/Day25.scala b/2017/src/main/scala/aoc2017/Day25.scala
index 7944e269..56bd2bd1 100644
--- a/2017/src/main/scala/aoc2017/Day25.scala
+++ b/2017/src/main/scala/aoc2017/Day25.scala
@@ -9,6 +9,8 @@ object Day25 extends AoC:
     case L, R
 
   import Move.*
+  
+  given CanEqual[Move, Move] = CanEqual.derived
 
   type State       = String
   type Value       = Int
diff --git a/2017/src/test/scala/aoc2017/Test2017.scala b/2017/src/test/scala/aoc2017/Test2017.scala
index be51a3d6..ba8cc3b2 100644
--- a/2017/src/test/scala/aoc2017/Test2017.scala
+++ b/2017/src/test/scala/aoc2017/Test2017.scala
@@ -3,6 +3,8 @@ package aoc2017
 import org.scalatest.funsuite.AnyFunSuite
 
 class Test2017 extends AnyFunSuite:
+
+  given CanEqual[Any, Any] = CanEqual.derived
   
   test("Day 1: Inverse Captcha"):
     assertResult(1069)(Day01.answer1)
diff --git a/2018/src/main/scala/aoc2018/Day02.scala b/2018/src/main/scala/aoc2018/Day02.scala
index f7991b3e..8a8a9063 100644
--- a/2018/src/main/scala/aoc2018/Day02.scala
+++ b/2018/src/main/scala/aoc2018/Day02.scala
@@ -18,6 +18,9 @@ object Day02 extends AoC:
       idLettersWith(3) >= 1
 
   object Box:
+
+    given CanEqual[Box, Box] = CanEqual.derived
+
     val IdCharSet: String = "abcdefghijklmnopqrstuvwxyz"
     def fromString(id: String): Box = Box(id)
 
diff --git a/2018/src/main/scala/aoc2018/Day03.scala b/2018/src/main/scala/aoc2018/Day03.scala
index d40c0841..13c30734 100644
--- a/2018/src/main/scala/aoc2018/Day03.scala
+++ b/2018/src/main/scala/aoc2018/Day03.scala
@@ -1,7 +1,7 @@
 package aoc2018
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 object Day03 extends AoC:
 
diff --git a/2018/src/main/scala/aoc2018/Day04.scala b/2018/src/main/scala/aoc2018/Day04.scala
index 907badbd..d6f9c905 100644
--- a/2018/src/main/scala/aoc2018/Day04.scala
+++ b/2018/src/main/scala/aoc2018/Day04.scala
@@ -12,6 +12,8 @@ object Day04 extends AoC:
 
   import Event.*
 
+  given CanEqual[Event, Event] = CanEqual.derived
+
   type Timestamp = String
 
   case class Record(timestamp: Timestamp, event: Event):
diff --git a/2018/src/main/scala/aoc2018/Day06.scala b/2018/src/main/scala/aoc2018/Day06.scala
index 8f872831..4f10da22 100644
--- a/2018/src/main/scala/aoc2018/Day06.scala
+++ b/2018/src/main/scala/aoc2018/Day06.scala
@@ -1,7 +1,7 @@
 package aoc2018
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 import scala.collection.+:
 import scala.collection.immutable.Vector
diff --git a/2018/src/main/scala/aoc2018/Day10.scala b/2018/src/main/scala/aoc2018/Day10.scala
index 774f548a..48fc713b 100644
--- a/2018/src/main/scala/aoc2018/Day10.scala
+++ b/2018/src/main/scala/aoc2018/Day10.scala
@@ -1,7 +1,7 @@
 package aoc2018
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 import scala.annotation.*
 import scala.math.Integral.Implicits.*
diff --git a/2018/src/main/scala/aoc2018/Day11.scala b/2018/src/main/scala/aoc2018/Day11.scala
index 2ecd8f35..246033f8 100644
--- a/2018/src/main/scala/aoc2018/Day11.scala
+++ b/2018/src/main/scala/aoc2018/Day11.scala
@@ -1,7 +1,7 @@
 package aoc2018
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 import scala.collection.*
 
diff --git a/2018/src/main/scala/aoc2018/Day13.scala b/2018/src/main/scala/aoc2018/Day13.scala
index c492eaea..cdc2dfb4 100644
--- a/2018/src/main/scala/aoc2018/Day13.scala
+++ b/2018/src/main/scala/aoc2018/Day13.scala
@@ -50,6 +50,8 @@ object Day13 extends AoC:
         case Straight => Right
         case Right    => Left
 
+  given CanEqual[Turn, Turn] = CanEqual.derived
+
   case class Cart(pos: Pos, dir: Dir, atIntersection: Turn = Turn.Left):
 
     def move(grid: Grid): Cart =
diff --git a/2018/src/main/scala/aoc2018/Day15.scala b/2018/src/main/scala/aoc2018/Day15.scala
index fef0b2d5..596c8159 100644
--- a/2018/src/main/scala/aoc2018/Day15.scala
+++ b/2018/src/main/scala/aoc2018/Day15.scala
@@ -1,7 +1,7 @@
 package aoc2018
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 import scala.annotation.tailrec
 import scala.util.Try
@@ -22,10 +22,13 @@ object Day15 extends AoC:
 
   import FighterType.*
 
+  given CanEqual[FighterType, FighterType] = CanEqual.derived
+
   case class Fighter(fighterType: FighterType, pos: Pos, hitPoints: Int = 200, attackPower: Int = 3)
 
-  given Ordering[Pos]     = Ordering.by(_.toTuple.swap)
-  given Ordering[Fighter] = Ordering.by(_.pos)
+  given Ordering[Pos]              = Ordering.by(_.toTuple.swap)
+  given Ordering[Fighter]          = Ordering.by(_.pos)
+  given CanEqual[Fighter, Fighter] = CanEqual.derived
 
   def targetsOf(fighter: Fighter)(using fighters: List[Fighter]): Set[Fighter] =
     fighters.filter(_.fighterType == fighter.fighterType.target).toSet
diff --git a/2018/src/main/scala/aoc2018/Day16.scala b/2018/src/main/scala/aoc2018/Day16.scala
index c2285029..08941cf8 100644
--- a/2018/src/main/scala/aoc2018/Day16.scala
+++ b/2018/src/main/scala/aoc2018/Day16.scala
@@ -63,6 +63,8 @@ object Day16 extends AoC:
         case EQRI => mem.setRI(a, b, c, (a: Int) => (b: Int) => if a == b then 1 else 0)
         case EQRR => mem.setRR(a, b, c, (a: Int) => (b: Int) => if a == b then 1 else 0)
 
+  given CanEqual[Inst, Inst] = CanEqual.derived
+  
   type Test  = (Mem, Codes, Mem)
 
   extension (test: Test)
diff --git a/2018/src/main/scala/aoc2018/Day17.scala b/2018/src/main/scala/aoc2018/Day17.scala
index 4ed80c82..83689227 100644
--- a/2018/src/main/scala/aoc2018/Day17.scala
+++ b/2018/src/main/scala/aoc2018/Day17.scala
@@ -1,7 +1,7 @@
 package aoc2018
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 object Day17 extends AoC:
 
@@ -16,6 +16,8 @@ object Day17 extends AoC:
     case Stopped
     case Flowing
 
+  given CanEqual[Stream, Stream] = CanEqual.derived
+
   import Stream.*
 
   import Iterator.*
diff --git a/2018/src/main/scala/aoc2018/Day18.scala b/2018/src/main/scala/aoc2018/Day18.scala
index ca0dc639..b1b592c1 100644
--- a/2018/src/main/scala/aoc2018/Day18.scala
+++ b/2018/src/main/scala/aoc2018/Day18.scala
@@ -1,7 +1,7 @@
 package aoc2018
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 import nmcb.predef.*
 
 import scala.collection.*
diff --git a/2018/src/main/scala/aoc2018/Day22.scala b/2018/src/main/scala/aoc2018/Day22.scala
index e9598e0e..5956c343 100644
--- a/2018/src/main/scala/aoc2018/Day22.scala
+++ b/2018/src/main/scala/aoc2018/Day22.scala
@@ -12,6 +12,8 @@ object Day22 extends AoC:
     case Wet    extends RegionType(1)
     case Narrow extends RegionType(2)
 
+  given CanEqual[RegionType, RegionType] = CanEqual.derived
+  
   case class Region(x: Int, y: Int):
     infix def +(x: Int, y: Int): Region    = copy(x = this.x + x, y = this.y + y)
     infix def manhattan(that: Region): Int = (x - that.x).abs + (y - that.y).abs
@@ -23,6 +25,8 @@ object Day22 extends AoC:
 
 
   object Region:
+    
+    given CanEqual[Region, Region] = CanEqual.derived
 
     val depth: Int     = 11817
     val mouth: Region  = Region(0, 0)
@@ -55,6 +59,8 @@ object Day22 extends AoC:
     case Torch
     case ClimbingGear
 
+  given CanEqual[Tool, Tool] = CanEqual.derived
+  
   import RegionType.*
   import Tool.*
 
diff --git a/2018/src/main/scala/aoc2018/Day23.scala b/2018/src/main/scala/aoc2018/Day23.scala
index d66e5a36..f71f3b5b 100644
--- a/2018/src/main/scala/aoc2018/Day23.scala
+++ b/2018/src/main/scala/aoc2018/Day23.scala
@@ -14,6 +14,8 @@ object Day23 extends AoC:
     infix def hasOverlappingRadiusWith(that: Bot): Boolean =
       loc.manhattan(that.loc) <= radius + that.radius
 
+  given CanEqual[Bot, Bot] = CanEqual.derived
+
   val bots: Set[Bot] =
     lines
       .collect:
diff --git a/2018/src/main/scala/aoc2018/Day24.scala b/2018/src/main/scala/aoc2018/Day24.scala
index 052124ff..e2cdbe8c 100644
--- a/2018/src/main/scala/aoc2018/Day24.scala
+++ b/2018/src/main/scala/aoc2018/Day24.scala
@@ -13,6 +13,8 @@ object Day24 extends AoC:
     case Infection
 
   import Army.*
+  
+  given CanEqual[Army, Army] = CanEqual.derived
 
   type AttackKind = String
 
diff --git a/2019/src/main/scala/aoc2019/Day03.scala b/2019/src/main/scala/aoc2019/Day03.scala
index 76d93d07..c9c34413 100644
--- a/2019/src/main/scala/aoc2019/Day03.scala
+++ b/2019/src/main/scala/aoc2019/Day03.scala
@@ -1,7 +1,7 @@
 package aoc2019
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 object Day03 extends AoC:
 
diff --git a/2019/src/main/scala/aoc2019/Day08.scala b/2019/src/main/scala/aoc2019/Day08.scala
index 27fed520..5093a588 100644
--- a/2019/src/main/scala/aoc2019/Day08.scala
+++ b/2019/src/main/scala/aoc2019/Day08.scala
@@ -11,6 +11,8 @@ object Day08 extends AoC:
   type Line[A] = List[A]
 
   case class Layer[A](digs: List[Line[A]]):
+    
+    given CanEqual[A, Dig] = CanEqual.derived
 
     def count(d: Dig): Int =
       digs.foldLeft(0)((a, l) => a + l.count(_ == d))
@@ -50,6 +52,8 @@ object Day08 extends AoC:
     case Trans
     case White
 
+    given CanEqual[Pix, Pix] = CanEqual.derived
+
     def render: Char =
       this match
         case Black => '░'
@@ -63,7 +67,7 @@ object Day08 extends AoC:
         case (_, Trans) => this
 
   import Pix.*
-
+  
   extension (dig: Dig)
 
     def digitToPix: Pix =
diff --git a/2019/src/main/scala/aoc2019/Day11.scala b/2019/src/main/scala/aoc2019/Day11.scala
index cc95c352..abcc2303 100644
--- a/2019/src/main/scala/aoc2019/Day11.scala
+++ b/2019/src/main/scala/aoc2019/Day11.scala
@@ -1,7 +1,7 @@
 package aoc2019
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 import scala.annotation.tailrec
 
 object Day11 extends AoC:
diff --git a/2019/src/main/scala/aoc2019/Day13.scala b/2019/src/main/scala/aoc2019/Day13.scala
index 9d4d47af..9eae97fa 100644
--- a/2019/src/main/scala/aoc2019/Day13.scala
+++ b/2019/src/main/scala/aoc2019/Day13.scala
@@ -20,6 +20,8 @@ object Day13 extends AoC:
 
   import Tile.*
 
+  given CanEqual[Tile, Tile] = CanEqual.derived
+
   case class Location(x: Long, y: Long)
 
   extension (outputs: LazyList[Value])
diff --git a/2019/src/main/scala/aoc2019/Day15.scala b/2019/src/main/scala/aoc2019/Day15.scala
index 86431375..6f0ff5c4 100644
--- a/2019/src/main/scala/aoc2019/Day15.scala
+++ b/2019/src/main/scala/aoc2019/Day15.scala
@@ -1,7 +1,7 @@
 package aoc2019
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 import scala.collection.*
 import scala.collection.immutable.Map
diff --git a/2019/src/main/scala/aoc2019/Day17.scala b/2019/src/main/scala/aoc2019/Day17.scala
index 922a5429..b86d7bdc 100644
--- a/2019/src/main/scala/aoc2019/Day17.scala
+++ b/2019/src/main/scala/aoc2019/Day17.scala
@@ -1,7 +1,7 @@
 package aoc2019
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 object Day17 extends AoC:
 
diff --git a/2019/src/main/scala/aoc2019/Day18.scala b/2019/src/main/scala/aoc2019/Day18.scala
index 1ea0a3ed..f9660e06 100644
--- a/2019/src/main/scala/aoc2019/Day18.scala
+++ b/2019/src/main/scala/aoc2019/Day18.scala
@@ -1,7 +1,7 @@
 package aoc2019
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 object Day18 extends AoC:
 
diff --git a/2019/src/main/scala/aoc2019/Day20.scala b/2019/src/main/scala/aoc2019/Day20.scala
index 93ab1b70..e5316a46 100644
--- a/2019/src/main/scala/aoc2019/Day20.scala
+++ b/2019/src/main/scala/aoc2019/Day20.scala
@@ -1,7 +1,7 @@
 package aoc2019
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 object Day20 extends AoC:
 
@@ -14,6 +14,8 @@ object Day20 extends AoC:
     case Inner(label: String)
 
   import Portal.*
+  
+  given CanEqual[Portal, Portal] = CanEqual.derived
 
   def portalToPortalRoutes(lines: Seq[String]): Map[Portal,Set[(Portal,Int)]] =
     def peek(x: Int, y: Int): Char = lines.lift(y).flatMap(_.lift(x)).getOrElse(' ')
diff --git a/2020/src/main/scala/aoc2020/Day20.scala b/2020/src/main/scala/aoc2020/Day20.scala
index 2b3605d6..b6cdd88b 100644
--- a/2020/src/main/scala/aoc2020/Day20.scala
+++ b/2020/src/main/scala/aoc2020/Day20.scala
@@ -1,7 +1,7 @@
 package aoc2020
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 import nmcb.predef.*
 
 import scala.annotation.tailrec
diff --git a/2020/src/main/scala/aoc2020/Day23.scala b/2020/src/main/scala/aoc2020/Day23.scala
index def67f5e..7f5e21e0 100644
--- a/2020/src/main/scala/aoc2020/Day23.scala
+++ b/2020/src/main/scala/aoc2020/Day23.scala
@@ -7,6 +7,8 @@ object Day23 extends AoC:
 
   /** a singe linked, updatable list of cups */
   case class Cup(value: Int, var next: Cup = null)
+  
+  given CanEqual[Cup, Cup] = CanEqual.derived
 
   def play(digits: Vector[Int], max: Int): Cup =
 
diff --git a/2021/src/main/scala/aoc2021/Day03.scala b/2021/src/main/scala/aoc2021/Day03.scala
index 9b21d56b..f71d1989 100644
--- a/2021/src/main/scala/aoc2021/Day03.scala
+++ b/2021/src/main/scala/aoc2021/Day03.scala
@@ -37,10 +37,10 @@ object Day03 extends AoC:
     filter(bits).toInt
 
 
-  lazy val gamma   = diagnostics.transpose.map(_.mostCommon).toInt
-  lazy val epsilon = diagnostics.transpose.map(_.leastCommon).toInt
-  override lazy val answer1 = gamma * epsilon
+  lazy val gamma: Int            = diagnostics.transpose.map(_.mostCommon).toInt
+  lazy val epsilon: Int          = diagnostics.transpose.map(_.leastCommon).toInt
+  override lazy val answer1: Int = gamma * epsilon
 
-  lazy val oxygenRating       = rating(diagnostics, _.mostCommon)
-  lazy val co2SchrubberRating = rating(diagnostics, _.leastCommon)
-  override lazy val answer2            = oxygenRating * co2SchrubberRating
+  lazy val oxygenRating: Int       = rating(diagnostics, _.mostCommon)
+  lazy val co2SchrubberRating: Int = rating(diagnostics, _.leastCommon)
+  override lazy val answer2: Int   = oxygenRating * co2SchrubberRating
diff --git a/2021/src/main/scala/aoc2021/Day04.scala b/2021/src/main/scala/aoc2021/Day04.scala
index 30bae6b3..7e9b87f2 100644
--- a/2021/src/main/scala/aoc2021/Day04.scala
+++ b/2021/src/main/scala/aoc2021/Day04.scala
@@ -54,6 +54,8 @@ object Day04 extends AoC:
 
 
   object Board:
+    
+    given [A] => CanEqual[Board[A], Board[A]] = CanEqual.derived
 
     def empty[A]: Board[A] =
       Board[A](Vector.empty)
@@ -66,6 +68,7 @@ object Day04 extends AoC:
 
   @tailrec
   def playWhoWinsLast[A](draws: Vector[A], game: Vector[Board[A]] = boards): Board[A] =
+    given CanEqual[A, A] = CanEqual.derived
     val round = game.map(_.draw(draws.head))
     val todo  = round.filterNot(_.hasBingo)
     if todo.nonEmpty then
diff --git a/2021/src/main/scala/aoc2021/Day09.scala b/2021/src/main/scala/aoc2021/Day09.scala
index 88029ee2..3ca9dda0 100644
--- a/2021/src/main/scala/aoc2021/Day09.scala
+++ b/2021/src/main/scala/aoc2021/Day09.scala
@@ -1,7 +1,7 @@
 package aoc2021
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 import scala.annotation.tailrec
 
diff --git a/2021/src/main/scala/aoc2021/Day13.scala b/2021/src/main/scala/aoc2021/Day13.scala
index 7c46f46b..6378144b 100644
--- a/2021/src/main/scala/aoc2021/Day13.scala
+++ b/2021/src/main/scala/aoc2021/Day13.scala
@@ -1,7 +1,7 @@
 package aoc2021
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 object Day13 extends AoC:
 
@@ -9,6 +9,8 @@ object Day13 extends AoC:
     case Ver, Hor
 
   import Axis.*
+  
+  given CanEqual[Axis, Axis] = CanEqual.derived
 
   type Dots  = Set[Pos]
   type Folds = Vector[(Axis, Int)]
diff --git a/2021/src/main/scala/aoc2021/Day15.scala b/2021/src/main/scala/aoc2021/Day15.scala
index 5568228b..43c90fb7 100644
--- a/2021/src/main/scala/aoc2021/Day15.scala
+++ b/2021/src/main/scala/aoc2021/Day15.scala
@@ -1,7 +1,7 @@
 package aoc2021
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 import scala.math.Integral.Implicits.infixIntegralOps
 
diff --git a/2021/src/main/scala/aoc2021/Day16.scala b/2021/src/main/scala/aoc2021/Day16.scala
index c53c65a5..0b058776 100644
--- a/2021/src/main/scala/aoc2021/Day16.scala
+++ b/2021/src/main/scala/aoc2021/Day16.scala
@@ -29,6 +29,8 @@ object Day16 extends AoC:
         case I => "1"
 
   import Bit.*
+  
+  given CanEqual[Bit, Bit] = CanEqual.derived
 
   type Version = Int       // 3 lsb
   type Id      = Int       // 3 lsb
diff --git a/2021/src/main/scala/aoc2021/Day20.scala b/2021/src/main/scala/aoc2021/Day20.scala
index 9b9998c2..1f4dd74e 100644
--- a/2021/src/main/scala/aoc2021/Day20.scala
+++ b/2021/src/main/scala/aoc2021/Day20.scala
@@ -1,7 +1,7 @@
 package aoc2021
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 object Day20 extends AoC:
 
diff --git a/2021/src/main/scala/aoc2021/Day22.scala b/2021/src/main/scala/aoc2021/Day22.scala
index e9868565..69db74ab 100644
--- a/2021/src/main/scala/aoc2021/Day22.scala
+++ b/2021/src/main/scala/aoc2021/Day22.scala
@@ -37,6 +37,7 @@ object Day22 extends AoC:
     def max(that: Position): Position =
       Position(x.max(that.x), y.max(that.y), z.max(that.z))
 
+  given CanEqual[Position, Position] = CanEqual.derived
 
   case class Cuboid(all: Map[Position,Boolean]):
 
diff --git a/2021/src/main/scala/aoc2021/Day25.scala b/2021/src/main/scala/aoc2021/Day25.scala
index 7d96578b..625bc186 100644
--- a/2021/src/main/scala/aoc2021/Day25.scala
+++ b/2021/src/main/scala/aoc2021/Day25.scala
@@ -1,7 +1,7 @@
 package aoc2021
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 import scala.annotation.tailrec
 
@@ -27,7 +27,8 @@ object Day25 extends AoC:
       val southTiles   = southRemoved ++ southUpdated ++ southMoved
       copy(tiles = southTiles)
 
-
+  given CanEqual[Floor, Floor] = CanEqual.derived
+  
   val floor: Floor =
     val sizeX = lines.head.size
     val sizeY = lines.size
diff --git a/2021/src/test/scala/aoc2021/Test2021.scala b/2021/src/test/scala/aoc2021/Test2021.scala
index 7b2140a9..a684d491 100644
--- a/2021/src/test/scala/aoc2021/Test2021.scala
+++ b/2021/src/test/scala/aoc2021/Test2021.scala
@@ -3,6 +3,8 @@ package aoc2021
 import org.scalatest.funsuite.AnyFunSuite
 
 class Test2021 extends AnyFunSuite:
+  
+  given CanEqual[Any, Any] = CanEqual.derived
 
   test("Day 1: Sonar Sweep"):
     assertResult(1602)(Day01.answer1)
diff --git a/2022/src/main/scala/aoc2022/Day09.scala b/2022/src/main/scala/aoc2022/Day09.scala
index 311a5ccb..cedb4604 100644
--- a/2022/src/main/scala/aoc2022/Day09.scala
+++ b/2022/src/main/scala/aoc2022/Day09.scala
@@ -11,6 +11,8 @@ object Day09 extends AoC:
     case L
 
   import Direction.*
+  
+  given CanEqual[Direction, Direction] = CanEqual.derived
 
   case class Position(x: Int, y: Int):
 
@@ -58,6 +60,9 @@ object Day09 extends AoC:
       alignment(h).foldLeft(this)(_ move _)
 
   object Position:
+    
+    given CanEqual[Position, Position] = CanEqual.derived
+    
     def of(x: Int, y: Int): Position = Position(x,y)
 
   case class Command(direction: Direction, steps: Int)
diff --git a/2022/src/main/scala/aoc2022/Day10.scala b/2022/src/main/scala/aoc2022/Day10.scala
index f89ba427..f791ecd4 100644
--- a/2022/src/main/scala/aoc2022/Day10.scala
+++ b/2022/src/main/scala/aoc2022/Day10.scala
@@ -9,6 +9,8 @@ object Day10 extends AoC:
   sealed trait Inst
   case object Nop                             extends Inst
   case class  Add(value: Int, steps: Int = 2) extends Inst
+  
+  given CanEqual[Inst, Inst] = CanEqual.derived
 
   lazy val instructions: Vector[Inst] =
     lines
diff --git a/2022/src/main/scala/aoc2022/Day12.scala b/2022/src/main/scala/aoc2022/Day12.scala
index 9c4b1210..1ec52dc2 100644
--- a/2022/src/main/scala/aoc2022/Day12.scala
+++ b/2022/src/main/scala/aoc2022/Day12.scala
@@ -1,7 +1,7 @@
 package aoc2022
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 object Day12 extends AoC:
 
diff --git a/2022/src/main/scala/aoc2022/Day13.scala b/2022/src/main/scala/aoc2022/Day13.scala
index 1691094a..3e87155a 100644
--- a/2022/src/main/scala/aoc2022/Day13.scala
+++ b/2022/src/main/scala/aoc2022/Day13.scala
@@ -8,6 +8,8 @@ object Day13 extends AoC:
   enum E:
     case N(n: Long)
     case L(l: List[E])
+    
+  given CanEqual[E, E] = CanEqual.derived    
 
   object E:
     def L(es: E*): L = L(es.toList)
diff --git a/2022/src/main/scala/aoc2022/Day14.scala b/2022/src/main/scala/aoc2022/Day14.scala
index f49a272e..f2a70dc2 100644
--- a/2022/src/main/scala/aoc2022/Day14.scala
+++ b/2022/src/main/scala/aoc2022/Day14.scala
@@ -1,7 +1,7 @@
 package aoc2022
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 import scala.annotation.*
 
@@ -11,6 +11,8 @@ object Day14 extends AoC:
     case Sand
     case Air
     case Rock
+    
+  given CanEqual[Tile, Tile] = CanEqual.derived    
 
   def parseLine(line: String): Vector[Pos] =
     line.trim
diff --git a/2022/src/main/scala/aoc2022/Day15.scala b/2022/src/main/scala/aoc2022/Day15.scala
index a6a368d1..3dce2fa2 100644
--- a/2022/src/main/scala/aoc2022/Day15.scala
+++ b/2022/src/main/scala/aoc2022/Day15.scala
@@ -1,7 +1,7 @@
 package aoc2022
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 object Day15 extends AoC:
 
diff --git a/2022/src/main/scala/aoc2022/Day17.scala b/2022/src/main/scala/aoc2022/Day17.scala
index b3a373e4..38728302 100644
--- a/2022/src/main/scala/aoc2022/Day17.scala
+++ b/2022/src/main/scala/aoc2022/Day17.scala
@@ -1,7 +1,7 @@
 package aoc2022
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 import nmcb.predef.*
 
 import scala.annotation.*
diff --git a/2022/src/main/scala/aoc2022/Day19.scala b/2022/src/main/scala/aoc2022/Day19.scala
index 53c43833..ac20c59c 100644
--- a/2022/src/main/scala/aoc2022/Day19.scala
+++ b/2022/src/main/scala/aoc2022/Day19.scala
@@ -35,7 +35,12 @@ object Day19 extends AoC:
 
   import Material.*
 
+  given CanEqual[Material, Material] = CanEqual.derived
+
+
   case class Robot(material: Material)
+  
+  given CanEqual[Robot, Robot] = CanEqual.derived
 
   case class MaterialStash(ore: Int = 0, clay: Int = 0, obsidian: Int = 0, geode: Int = 0)
 
@@ -47,6 +52,8 @@ object Day19 extends AoC:
     case GeodeRobot
 
   import Build.*
+  
+  given CanEqual[Build, Build] = CanEqual.derived
 
   def buildActions(print: Blueprint, material: MaterialStash, robots: Vector[Robot]): Vector[Build] =
     import material.*
diff --git a/2022/src/main/scala/aoc2022/Day22.scala b/2022/src/main/scala/aoc2022/Day22.scala
index d1c15a45..6fd424b9 100644
--- a/2022/src/main/scala/aoc2022/Day22.scala
+++ b/2022/src/main/scala/aoc2022/Day22.scala
@@ -1,7 +1,7 @@
 package aoc2022
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 object Day22 extends AoC:
 
diff --git a/2022/src/main/scala/aoc2022/Day23.scala b/2022/src/main/scala/aoc2022/Day23.scala
index 070df08f..9dd11b44 100644
--- a/2022/src/main/scala/aoc2022/Day23.scala
+++ b/2022/src/main/scala/aoc2022/Day23.scala
@@ -1,7 +1,7 @@
 package aoc2022
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 import scala.annotation.tailrec
 
diff --git a/2022/src/main/scala/aoc2022/Day24.scala b/2022/src/main/scala/aoc2022/Day24.scala
index 3556346f..54d5231c 100644
--- a/2022/src/main/scala/aoc2022/Day24.scala
+++ b/2022/src/main/scala/aoc2022/Day24.scala
@@ -22,6 +22,8 @@ object Day24 extends AoC:
     case Left  extends Dir(char = Field.LeftChar)
     case Right extends Dir(char = Field.RightChar)
 
+  given CanEqual[Dir, Dir] = CanEqual.derived
+
   type Field[A] = Vector[Vector[A]]
 
   object Field:
diff --git a/2023/src/main/scala/aoc2023/Day03.scala b/2023/src/main/scala/aoc2023/Day03.scala
index 65c8a2d3..37646509 100644
--- a/2023/src/main/scala/aoc2023/Day03.scala
+++ b/2023/src/main/scala/aoc2023/Day03.scala
@@ -1,7 +1,7 @@
 package aoc2023
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 import scala.annotation.*
 
@@ -67,7 +67,7 @@ object Day03 extends AoC:
         for
           (g1, ns1) <- gearsWithAdjacentNumbers
           (g2, ns2) <- gearsWithAdjacentNumbers
-          if g1 == g2 && ns1.size == 2 && ns2.size == 2 && ns1 == ns2
+          if g1 == g2 && ns1.size == 2 && ns2.size == 2 && (ns1 diff ns2).isEmpty
         yield ns1
       ratios.toVector
 
diff --git a/2023/src/main/scala/aoc2023/Day07.scala b/2023/src/main/scala/aoc2023/Day07.scala
index 3b29bb36..45efee7f 100644
--- a/2023/src/main/scala/aoc2023/Day07.scala
+++ b/2023/src/main/scala/aoc2023/Day07.scala
@@ -21,6 +21,8 @@ object Day07 extends AoC:
     case FiveOfAKind
 
   import Strength.*
+  
+  given CanEqual[Strength, Strength] = CanEqual.derived
 
   given Ordering[Strength] with
 
diff --git a/2023/src/main/scala/aoc2023/Day10.scala b/2023/src/main/scala/aoc2023/Day10.scala
index c98a45df..c4a439c7 100644
--- a/2023/src/main/scala/aoc2023/Day10.scala
+++ b/2023/src/main/scala/aoc2023/Day10.scala
@@ -1,7 +1,7 @@
 package aoc2023
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 import scala.annotation.tailrec
 
@@ -20,6 +20,8 @@ object Day10 extends AoC:
       if directions.contains(d.opposite) then directions.find(_ != d.opposite) else None
 
   import Tile.*
+  
+  given CanEqual[Tile, Tile] = CanEqual.derived
 
   object Tile:
     def fromChar(c: Char): Tile =
diff --git a/2023/src/main/scala/aoc2023/Day11.scala b/2023/src/main/scala/aoc2023/Day11.scala
index 02ffe5ba..4bd7d440 100644
--- a/2023/src/main/scala/aoc2023/Day11.scala
+++ b/2023/src/main/scala/aoc2023/Day11.scala
@@ -1,7 +1,7 @@
 package aoc2023
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 object Day11 extends AoC:
 
diff --git a/2023/src/main/scala/aoc2023/Day16.scala b/2023/src/main/scala/aoc2023/Day16.scala
index 43b6c35b..4708473d 100644
--- a/2023/src/main/scala/aoc2023/Day16.scala
+++ b/2023/src/main/scala/aoc2023/Day16.scala
@@ -1,7 +1,7 @@
 package aoc2023
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 import scala.annotation.tailrec
 
diff --git a/2023/src/main/scala/aoc2023/Day17.scala b/2023/src/main/scala/aoc2023/Day17.scala
index 9e310a7d..01e3db5c 100644
--- a/2023/src/main/scala/aoc2023/Day17.scala
+++ b/2023/src/main/scala/aoc2023/Day17.scala
@@ -2,7 +2,7 @@ package aoc2023
 
 import nmcb.*
 import nmcb.predef.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 import scala.collection.mutable
 
diff --git a/2023/src/main/scala/aoc2023/Day18.scala b/2023/src/main/scala/aoc2023/Day18.scala
index 686f6920..3f56a6e9 100644
--- a/2023/src/main/scala/aoc2023/Day18.scala
+++ b/2023/src/main/scala/aoc2023/Day18.scala
@@ -1,7 +1,7 @@
 package aoc2023
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 import scala.annotation.tailrec
 
diff --git a/2023/src/main/scala/aoc2023/Day19.scala b/2023/src/main/scala/aoc2023/Day19.scala
index 5cc14daa..12880d9d 100644
--- a/2023/src/main/scala/aoc2023/Day19.scala
+++ b/2023/src/main/scala/aoc2023/Day19.scala
@@ -15,6 +15,8 @@ object Day19 extends AoC:
     case Compared(select1: Part => Boolean, select2: Long => Boolean, workflow: String, selector: Char)
 
   import Rule.*
+  
+  given CanEqual[Rule, Rule] = CanEqual.derived
 
   case class Range(from: Long, to: Long):
     def size: Long = to - from + 1
diff --git a/2023/src/main/scala/aoc2023/Day20.scala b/2023/src/main/scala/aoc2023/Day20.scala
index 6342036d..9913e56f 100644
--- a/2023/src/main/scala/aoc2023/Day20.scala
+++ b/2023/src/main/scala/aoc2023/Day20.scala
@@ -11,6 +11,8 @@ object Day20 extends AoC:
     case L
 
   import Pulse.*
+  
+  given CanEqual[Pulse, Pulse] = CanEqual.derived
 
   type Name = String
   type Message = (Name, Name, Pulse)
diff --git a/2023/src/main/scala/aoc2023/Day21.scala b/2023/src/main/scala/aoc2023/Day21.scala
index 442a043e..0caae601 100644
--- a/2023/src/main/scala/aoc2023/Day21.scala
+++ b/2023/src/main/scala/aoc2023/Day21.scala
@@ -1,7 +1,7 @@
 package aoc2023
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 import scala.annotation.tailrec
 
diff --git a/2023/src/main/scala/aoc2023/Day22.scala b/2023/src/main/scala/aoc2023/Day22.scala
index b078d943..321603a1 100644
--- a/2023/src/main/scala/aoc2023/Day22.scala
+++ b/2023/src/main/scala/aoc2023/Day22.scala
@@ -95,6 +95,8 @@ object Day22 extends AoC:
       intersect(that).isDefined
 
   object Box:
+    
+    given CanEqual[Box, Box] = CanEqual.derived
 
     def fromString(s: String): Box =
       s match
diff --git a/2023/src/main/scala/aoc2023/Day23.scala b/2023/src/main/scala/aoc2023/Day23.scala
index 16382d8e..d02c3beb 100644
--- a/2023/src/main/scala/aoc2023/Day23.scala
+++ b/2023/src/main/scala/aoc2023/Day23.scala
@@ -1,7 +1,7 @@
 package aoc2023
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 import scala.collection.mutable
 
diff --git a/2024/src/main/scala/aoc2024/Day04.scala b/2024/src/main/scala/aoc2024/Day04.scala
index d2bf292c..12f2eb74 100644
--- a/2024/src/main/scala/aoc2024/Day04.scala
+++ b/2024/src/main/scala/aoc2024/Day04.scala
@@ -1,7 +1,7 @@
 package aoc2024
 
 import nmcb.*
-import pos.*
+import pos.{*, given}
 
 object Day04 extends AoC:
 
diff --git a/2024/src/main/scala/aoc2024/Day06.scala b/2024/src/main/scala/aoc2024/Day06.scala
index 5d5b13b8..39f72310 100644
--- a/2024/src/main/scala/aoc2024/Day06.scala
+++ b/2024/src/main/scala/aoc2024/Day06.scala
@@ -1,7 +1,7 @@
 package aoc2024
 
 import nmcb.*
-import pos.*
+import pos.{*, given}
 
 import scala.annotation.*
 
diff --git a/2024/src/main/scala/aoc2024/Day08.scala b/2024/src/main/scala/aoc2024/Day08.scala
index 7883cd90..af05308a 100644
--- a/2024/src/main/scala/aoc2024/Day08.scala
+++ b/2024/src/main/scala/aoc2024/Day08.scala
@@ -1,7 +1,7 @@
 package aoc2024
 
 import nmcb.*
-import pos.*
+import pos.{*, given}
 import nmcb.predef.*
 
 object Day08 extends AoC:
diff --git a/2024/src/main/scala/aoc2024/Day09.scala b/2024/src/main/scala/aoc2024/Day09.scala
index 2580ebbb..6c06f94d 100644
--- a/2024/src/main/scala/aoc2024/Day09.scala
+++ b/2024/src/main/scala/aoc2024/Day09.scala
@@ -7,8 +7,8 @@ import scala.annotation.*
 object Day09 extends AoC:
 
   case class Block(id: Int):
-    def isFileBlock: Boolean = this != Block.free
-    def isFreeBlock: Boolean = this == Block.free
+    def isFileBlock: Boolean = this.id != Block.free.id
+    def isFreeBlock: Boolean = this.id == Block.free.id
     def asString: String     = if id == -1 then "." else id.toString
 
   object Block:
diff --git a/2024/src/main/scala/aoc2024/Day10.scala b/2024/src/main/scala/aoc2024/Day10.scala
index 6d3067bc..9eef080e 100644
--- a/2024/src/main/scala/aoc2024/Day10.scala
+++ b/2024/src/main/scala/aoc2024/Day10.scala
@@ -1,7 +1,7 @@
 package aoc2024
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 object Day10 extends AoC:
 
diff --git a/2024/src/main/scala/aoc2024/Day12.scala b/2024/src/main/scala/aoc2024/Day12.scala
index 0d771b62..2c31d6b0 100644
--- a/2024/src/main/scala/aoc2024/Day12.scala
+++ b/2024/src/main/scala/aoc2024/Day12.scala
@@ -2,7 +2,7 @@ package aoc2024
 
 import nmcb.*
 import nmcb.predef.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 import scala.annotation.*
 
diff --git a/2024/src/main/scala/aoc2024/Day14.scala b/2024/src/main/scala/aoc2024/Day14.scala
index 7cae0e7d..16e5e42c 100644
--- a/2024/src/main/scala/aoc2024/Day14.scala
+++ b/2024/src/main/scala/aoc2024/Day14.scala
@@ -1,7 +1,7 @@
 package aoc2024
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 import scala.annotation.*
 
diff --git a/2024/src/main/scala/aoc2024/Day15.scala b/2024/src/main/scala/aoc2024/Day15.scala
index e5d346b6..8169b051 100644
--- a/2024/src/main/scala/aoc2024/Day15.scala
+++ b/2024/src/main/scala/aoc2024/Day15.scala
@@ -1,7 +1,7 @@
 package aoc2024
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 import scala.annotation.*
 
diff --git a/2024/src/main/scala/aoc2024/Day16.scala b/2024/src/main/scala/aoc2024/Day16.scala
index 3d1b8042..4a566419 100644
--- a/2024/src/main/scala/aoc2024/Day16.scala
+++ b/2024/src/main/scala/aoc2024/Day16.scala
@@ -1,7 +1,7 @@
 package aoc2024
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 import nmcb.predef.*
 
 object Day16 extends AoC:
diff --git a/2024/src/main/scala/aoc2024/Day18.scala b/2024/src/main/scala/aoc2024/Day18.scala
index c6fbef1f..750a9344 100644
--- a/2024/src/main/scala/aoc2024/Day18.scala
+++ b/2024/src/main/scala/aoc2024/Day18.scala
@@ -1,7 +1,7 @@
 package aoc2024
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 import scala.annotation.*
 
diff --git a/2024/src/main/scala/aoc2024/Day20.scala b/2024/src/main/scala/aoc2024/Day20.scala
index 04cab1eb..290edd71 100644
--- a/2024/src/main/scala/aoc2024/Day20.scala
+++ b/2024/src/main/scala/aoc2024/Day20.scala
@@ -1,7 +1,7 @@
 package aoc2024
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 import scala.Option.*
 import scala.annotation.*
diff --git a/2024/src/main/scala/aoc2024/Day21.scala b/2024/src/main/scala/aoc2024/Day21.scala
index cd3df4b0..d01ea835 100644
--- a/2024/src/main/scala/aoc2024/Day21.scala
+++ b/2024/src/main/scala/aoc2024/Day21.scala
@@ -1,7 +1,7 @@
 package aoc2024
 
 import nmcb.*
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 import nmcb.predef.*
 
 import scala.collection.immutable.Map
diff --git a/2024/src/test/scala/aoc2024/Test2024.scala b/2024/src/test/scala/aoc2024/Test2024.scala
index 5f520b48..8f51ca88 100644
--- a/2024/src/test/scala/aoc2024/Test2024.scala
+++ b/2024/src/test/scala/aoc2024/Test2024.scala
@@ -1,6 +1,6 @@
 package aoc2024
 
-import nmcb.pos.*
+import nmcb.pos.{*, given}
 
 import org.scalatest.funsuite.AnyFunSuite
 
diff --git a/2025/src/main/scala/aoc2025/Day10.scala b/2025/src/main/scala/aoc2025/Day10.scala
index af560299..2a24f0f9 100644
--- a/2025/src/main/scala/aoc2025/Day10.scala
+++ b/2025/src/main/scala/aoc2025/Day10.scala
@@ -3,6 +3,7 @@ package aoc2025
 import nmcb.*
 import nmcb.predef.*
 
+import scala.CanEqual.derived
 import scala.annotation.*
 
 object Day10 extends AoC:
@@ -82,7 +83,6 @@ object Day10 extends AoC:
       import scala.jdk.CollectionConverters.*
 
       val ctx = new Context(Map("model" -> "true").asJava)
-      import ctx.*
 
       //        (3) (1,3) (2) (2,3) (0,2) (0,1) {3,5,4,7}
       //
@@ -97,33 +97,35 @@ object Day10 extends AoC:
       //      x0 = 1, x1 = 3, x2 = 3, x4 = 1, x5 = 2
 
 
-      val optimizer = mkOptimize()
+      val optimizer = ctx.mkOptimize()
 
       /** defines variables x0, x1, ... xn */
       val xs: Vector[IntExpr] =
         buttons
           .zipWithIndex
-          .map((_,i) => mkIntConst(s"x$i"))
+          .map((_,i) => ctx.mkIntConst(s"x$i"))
 
       /** add constraints x0 >= 0, x1 >= 0 ... xn >= 0 */
       for presses <- xs do
-        optimizer.Add(mkGe(presses, mkInt(0)))
+        optimizer.Add(ctx.mkGe(presses, ctx.mkInt(0)))
 
       /** add goal minimise for x0 + x1 + ... xn */
       val total: ArithExpr[IntSort] =
-        xs.foldLeft[ArithExpr[IntSort]](mkInt(0)): (x,y) =>
-          mkAdd(x,y)
+        xs.foldLeft[ArithExpr[IntSort]](ctx.mkInt(0)): (x,y) =>
+          ctx.mkAdd(x,y)
       optimizer.MkMinimize(total)
 
       /** joltage(i) - b(i0) - b(i1) - b(in) = 0 */
-      (buttons zip xs)
-        .foldLeft(joltages.map[ArithExpr[IntSort]](mkInt)):
+      buttons
+        .zip(xs)
+        .foldLeft(joltages.map[ArithExpr[IntSort]](ctx.mkInt)):
           case (expressions, (b, x)) =>
             b.indices.foldLeft(expressions): (expressions, i) =>
-              expressions.updated(i, mkSub(expressions(i), x))
+              expressions.updated(i, ctx.mkSub(expressions(i), x))
         .foreach: joltageLeft =>
-          optimizer.Add(mkEq(joltageLeft, mkInt(0)))
+          optimizer.Add(ctx.mkEq(joltageLeft, ctx.mkInt(0)))
 
+      given CanEqual[Status, Status] = CanEqual.derived
       assert(optimizer.Check() == Status.SATISFIABLE)
 
       optimizer.getModel.evaluate(total, false).toString.toInt
diff --git a/build.sbt b/build.sbt
index 8fd925f0..26a258bc 100644
--- a/build.sbt
+++ b/build.sbt
@@ -20,6 +20,7 @@ ThisBuild / scalacOptions ++= Seq(
   "-feature",
   "-language:implicitConversions",
   "-language:existentials",
+  "-language:strictEquality",
   "-unchecked",
   "-Werror",
   "-deprecation"
diff --git a/nmcb/src/main/scala/nmcb/AoC.scala b/nmcb/src/main/scala/nmcb/AoC.scala
index 3442600e..09c1a6fb 100644
--- a/nmcb/src/main/scala/nmcb/AoC.scala
+++ b/nmcb/src/main/scala/nmcb/AoC.scala
@@ -30,5 +30,5 @@ abstract class AoC:
     println(s"Answer $day part 1: $answer1 [${System.currentTimeMillis - start1}ms]")
 
     val start2: Long = System.currentTimeMillis
-    if answer2 != "<unimplemented>" then
+    if answer2.toString != "<unimplemented>" then
       println(s"Answer $day part 2: $answer2 [${System.currentTimeMillis - start2}ms]")
diff --git a/nmcb/src/main/scala/nmcb/Dijkstra.scala b/nmcb/src/main/scala/nmcb/Dijkstra.scala
index ebd03f9a..88caf45e 100644
--- a/nmcb/src/main/scala/nmcb/Dijkstra.scala
+++ b/nmcb/src/main/scala/nmcb/Dijkstra.scala
@@ -1,6 +1,6 @@
 package nmcb
 
-import pos.*
+import pos.{*, given}
 import predef.*
 
 import scala.annotation.*
@@ -30,7 +30,7 @@ object Dijkstra:
     def fromEdges[A](edges: Vector[Edge[A]]): Graph[A] =
       Graph(edges.groupMap(_.from)(identity))
 
-    def fromGrid[A](grid: Grid[A], node: A, dist: (Pos,Pos) => Int = (_,_) => 1): Graph[Pos] =
+    def fromGrid[A](grid: Grid[A], node: A, dist: (Pos,Pos) => Int = (_,_) => 1)(using CanEqual[A, A]): Graph[Pos] =
       grid.elements
         .filter(_.element == node)
         .foldLeft(Graph.empty): (graph,from) =>
@@ -61,7 +61,7 @@ object Dijkstra:
   import scala.collection.mutable
 
   /** classic dijkstra traverses the shortest found paths first */
-  def run[A](from: A, graph: A => Set[(A,Int)]): Result[A] =
+  def run[A](from: A, graph: A => Set[(A,Int)])(using CanEqual[A, A]): Result[A] =
     val edgeTo: mutable.Map[A,Edge[A]] = mutable.Map.empty
     val distTo: mutable.Map[A,Int]     = mutable.Map.empty.withDefaultValue(Int.MaxValue)
 
@@ -82,7 +82,7 @@ object Dijkstra:
     Result(edgeTo.toMap, distTo.toMap)
 
   /** classic dijkstra traverses the shortest found paths first */
-  def run[A](from: A, graph: Graph[A]): Result[A] =
+  def run[A](from: A, graph: Graph[A])(using CanEqual[A, A]): Result[A] =
     val edgeTo: mutable.Map[A, Edge[A]] = mutable.Map.empty
     val distTo: mutable.Map[A, Int] = mutable.Map.from(graph.neighbours.map((node, _) => node -> Int.MaxValue)).withDefaultValue(Int.MaxValue)
 
diff --git a/nmcb/src/main/scala/nmcb/Grid.scala b/nmcb/src/main/scala/nmcb/Grid.scala
index 6473cef9..759e88f5 100644
--- a/nmcb/src/main/scala/nmcb/Grid.scala
+++ b/nmcb/src/main/scala/nmcb/Grid.scala
@@ -1,7 +1,7 @@
 package nmcb
 
 import Dijkstra.*
-import pos.*
+import pos.{*, given}
 
 case class Grid[+A](matrix: Vector[Vector[A]]):
   val sizeY: Int = matrix.size
@@ -32,13 +32,13 @@ case class Grid[+A](matrix: Vector[Vector[A]]):
   def peekOrElse[A1 >: A](p: Pos, default: => A1): A1 =
     peekOption(p).getOrElse(default)
 
-  def find[A1 >: A](a: A1): Option[Pos] =
+  def find[A1 >: A](a: A1)(using CanEqual[A, A1]): Option[Pos] =
     elements.find(_.element == a).map(_.pos)
 
-  def findAll[A1 >: A](a: A1): Set[Pos] =
+  def findAll[A1 >: A](a: A1)(using CanEqual[A, A1]): Set[Pos] =
     elements.filter(_.element == a).map(_.pos)
 
-  def findOne[A1 >: A](a: A1, default: => Pos = sys.error(s"not found")): Pos =
+  def findOne[A1 >: A](a: A1, default: => Pos = sys.error(s"not found"))(using CanEqual[A, A1]): Pos =
     find(a).getOrElse(default)
 
   def filter[A1 >: A](f: ((Pos,A1)) => Boolean): Set[(Pos,A1)] =
@@ -59,7 +59,7 @@ case class Grid[+A](matrix: Vector[Vector[A]]):
   def asString: String =
     matrix.map(_.mkString("")).mkString("\n")
 
-  def extractPath[A1 >: A](from: A1, to: A1, node: A1): (Pos,Pos,Grid[A1]) =
+  def extractPath[A1 >: A](from: A1, to: A1, node: A1)(using CanEqual[A, A1]): (Pos,Pos,Grid[A1]) =
     val fromPos  = findOne(from)
     val toPos    = findOne(to)
     val cleared  = updated(fromPos, node).updated(toPos, node)
@@ -113,8 +113,10 @@ object Grid:
     def to: Pos   = g._2
     def cleared: Grid[A] = g._3
 
-    def shortest: Vector[Pos] =
+    def shortest: Vector[Pos] = {
+      given CanEqual[A, A] = CanEqual.derived
       Dijkstra
         .run(from, Graph.fromGrid(cleared, cleared.peek(from)))
         .pathTo(to)
         .toTrail
+    }
diff --git a/nmcb/src/main/scala/nmcb/pos.scala b/nmcb/src/main/scala/nmcb/pos.scala
index dcac9b31..f3192ef1 100644
--- a/nmcb/src/main/scala/nmcb/pos.scala
+++ b/nmcb/src/main/scala/nmcb/pos.scala
@@ -1,5 +1,7 @@
 package nmcb
 
+import scala.CanEqual.derived
+
 object pos:
 
   enum Dir:
@@ -26,12 +28,16 @@ object pos:
         case E => W
         case W => E
 
-  export Dir.*
+  export Dir.{*, given}
 
   type Pos = (x: Int, y: Int)
 
   given Ordering[Pos] = Ordering.by(_.toTuple)
 
+  given CanEqual[Pos, Pos] = CanEqual.derived
+
+  given CanEqual[Dir, Dir] = CanEqual.derived
+
 
   object Pos:
 
@@ -111,7 +117,7 @@ object pos:
     def adjoint8: Set[Pos] =
       Pos.offset8.map(_ + p)
 
-    infix inline def step(dir: Dir): Pos =
+    infix inline def step(dir: Dir)(using CanEqual[Dir, Dir]): Pos =
       dir match
         case N => (x = p.x, y = p.y - 1)
         case E => (x = p.x + 1, y = p.y)
diff --git a/nmcb/src/test/scala/nmcb/TestDijkstra.scala b/nmcb/src/test/scala/nmcb/TestDijkstra.scala
index baa1513b..4e673c90 100644
--- a/nmcb/src/test/scala/nmcb/TestDijkstra.scala
+++ b/nmcb/src/test/scala/nmcb/TestDijkstra.scala
@@ -1,7 +1,7 @@
 package nmcb
 
 import nmcb.*
-import pos.*
+import pos.{*, given}
 import nmcb.Dijkstra.*
 import nmcb.predef.*
 import org.scalatest.funsuite.AnyFunSuite