diff --git a/commonUI/src/main/kotlin/ch/dissem/yaep/ui/common/App.kt b/commonUI/src/main/kotlin/ch/dissem/yaep/ui/common/App.kt
index d3ed892..5040319 100644
--- a/commonUI/src/main/kotlin/ch/dissem/yaep/ui/common/App.kt
+++ b/commonUI/src/main/kotlin/ch/dissem/yaep/ui/common/App.kt
@@ -1,21 +1,45 @@
 package ch.dissem.yaep.ui.common
 
 import androidx.compose.foundation.BorderStroke
+import androidx.compose.foundation.ExperimentalFoundationApi
 import androidx.compose.foundation.Image
-import androidx.compose.foundation.clickable
-import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.PointerMatcher
+import androidx.compose.foundation.PointerMatcher.Companion.mouse
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.aspectRatio
+import androidx.compose.foundation.layout.fillMaxHeight
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.wrapContentHeight
 import androidx.compose.foundation.lazy.grid.GridCells
 import androidx.compose.foundation.lazy.grid.LazyVerticalGrid
+import androidx.compose.foundation.onClick
 import androidx.compose.material3.CardDefaults
 import androidx.compose.material3.HorizontalDivider
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.OutlinedCard
-import androidx.compose.runtime.*
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.alpha
 import androidx.compose.ui.draw.shadow
+import androidx.compose.ui.input.pointer.PointerButton.Companion.Secondary
 import androidx.compose.ui.unit.dp
-import ch.dissem.yaep.domain.*
+import ch.dissem.yaep.domain.Clue
+import ch.dissem.yaep.domain.Game
+import ch.dissem.yaep.domain.Grid
+import ch.dissem.yaep.domain.HorizontalClue
+import ch.dissem.yaep.domain.ItemClass
+import ch.dissem.yaep.domain.NeighbourClue
+import ch.dissem.yaep.domain.OrderClue
+import ch.dissem.yaep.domain.SameColumnClue
+import ch.dissem.yaep.domain.TripletClue
+import ch.dissem.yaep.domain.generateGame
 import org.jetbrains.compose.resources.painterResource
 import yaep.commonui.generated.resources.Res
 import yaep.commonui.generated.resources.neighbour
@@ -93,10 +117,15 @@ fun PuzzleGrid(
                             item.options.remove(it)
                             row.cleanupOptions()
                         },
+                        onOptionAdded = {
+                            item.options.add(it)
+                        },
                         selectedItem = selection,
                         onSelectItem = {
                             item.selection = it
-                            row.cleanupOptions()
+                            if (it != null) {
+                                row.cleanupOptions()
+                            }
                         }
                     )
                 }
@@ -147,10 +176,11 @@ fun PuzzleClues(
     }
 }
 
+@OptIn(ExperimentalFoundationApi::class)
 private fun Modifier.forClue(clue: DisplayClue<out Clue>) = this
     .alpha(if (clue.isActive) 1f else 0.2f)
     .padding(8.dp)
-    .clickable { clue.isActive = false }
+    .onClick(matcher = PointerMatcher.Primary + mouse(Secondary)) { clue.isActive = !clue.isActive }
 
 @Composable
 fun HorizontalClue(modifier: Modifier = Modifier, clue: HorizontalClue, isClueViolated: Boolean) {
@@ -191,7 +221,11 @@ fun HorizontalClue(modifier: Modifier = Modifier, clue: HorizontalClue, isClueVi
 }
 
 @Composable
-fun VerticalClue(modifier: Modifier = Modifier, clue: SameColumnClue<*, *>, isClueViolated: Boolean = false) {
+fun VerticalClue(
+    modifier: Modifier = Modifier,
+    clue: SameColumnClue<*, *>,
+    isClueViolated: Boolean = false
+) {
     ClueCard(
         modifier = modifier.aspectRatio(0.5f),
         isClueViolated = isClueViolated
@@ -204,11 +238,20 @@ fun VerticalClue(modifier: Modifier = Modifier, clue: SameColumnClue<*, *>, isCl
 }
 
 @Composable
-fun ClueCard(modifier: Modifier = Modifier, isClueViolated: Boolean, content: @Composable () -> Unit) {
+fun ClueCard(
+    modifier: Modifier = Modifier,
+    isClueViolated: Boolean,
+    content: @Composable () -> Unit
+) {
     val colors = MaterialTheme.colorScheme
     OutlinedCard(
         modifier = if (isClueViolated) {
-            modifier.shadow(8.dp, shape = CardDefaults.outlinedShape, ambientColor = colors.error, spotColor = colors.error)
+            modifier.shadow(
+                8.dp,
+                shape = CardDefaults.outlinedShape,
+                ambientColor = colors.error,
+                spotColor = colors.error
+            )
         } else {
             modifier
         },
diff --git a/commonUI/src/main/kotlin/ch/dissem/yaep/ui/common/selector.kt b/commonUI/src/main/kotlin/ch/dissem/yaep/ui/common/selector.kt
index ab80877..54cfcd7 100644
--- a/commonUI/src/main/kotlin/ch/dissem/yaep/ui/common/selector.kt
+++ b/commonUI/src/main/kotlin/ch/dissem/yaep/ui/common/selector.kt
@@ -28,7 +28,8 @@ import kotlin.math.min
 fun <C : ItemClass<C>> Selector(
     modifier: Modifier = Modifier,
     options: List<Toggleable<Item<C>>>,
-    onOptionRemoved: (Item<C>?) -> Unit,
+    onOptionRemoved: (Item<C>) -> Unit,
+    onOptionAdded: (Item<C>) -> Unit,
     selectedItem: Item<C>?,
     onSelectItem: (Item<C>?) -> Unit,
 ) {
@@ -54,8 +55,13 @@ fun <C : ItemClass<C>> Selector(
                                 .onClick(
                                     matcher = PointerMatcher.mouse(PointerButton.Secondary),
                                     onClick = {
-                                        option.enabled = false
-                                        onOptionRemoved(option.item)
+                                        if (option.enabled) {
+                                            option.enabled = false
+                                            onOptionRemoved(option.item)
+                                        } else {
+                                            option.enabled = true
+                                            onOptionAdded(option.item)
+                                        }
                                     }
                                 )
                         )
diff --git a/domain/src/main/kotlin/ch/dissem/yaep/domain/GameRow.kt b/domain/src/main/kotlin/ch/dissem/yaep/domain/GameRow.kt
index 074ebaa..23d3893 100644
--- a/domain/src/main/kotlin/ch/dissem/yaep/domain/GameRow.kt
+++ b/domain/src/main/kotlin/ch/dissem/yaep/domain/GameRow.kt
@@ -8,18 +8,49 @@ class GameRow<C : ItemClass<C>>(
     fun indexOf(element: C) = indexOfFirst { it.selection?.itemType == element }
 
     fun cleanupOptions() {
-        cells.forEach { cleanupOptions(it) }
+        cells.forEach {
+            cleanupOptions(it)
+        }
+//        do {
+//            var selectedSingleOption = false
+//            cells.forEach { cleanupOptions(it) }
+//            val selections = cells.mapNotNull { it.selection }
+//            options
+//                .filter { !selections.contains(it) }
+//                .forEach { option ->
+//                    if (cells.count { cell -> cell.options.contains(option) } == 1) {
+//                        cells
+//                            .filter { it.selection == null }
+//                            .first { cell -> cell.options.contains(option) }
+//                            .let { it.selection = option }
+//                        selectedSingleOption = true
+//                    }
+//                }
+//        } while (selectedSingleOption)
     }
 
-    private fun cleanupOptions(cell: GameCell<C>, firstCall: Boolean = true) {
-        if ((firstCall && cell.selection != null) || (cell.options.size == 1 && cell.selection == null)) {
-            if (cell.selection == null) {
+    private fun cleanupOptions(cell: GameCell<C>, justSelected: Boolean = true) {
+        if ((justSelected && cell.selection != null) || (cell.options.size == 1 && cell.selection == null)) {
+            val selection = cell.selection
+            if (selection == null) {
                 cell.selection = cell.options.first()
+            } else {
+                cell.options.clear()
+                cell.options.add(selection)
             }
-            filter { otherCell -> otherCell != cell && otherCell.selection == null }.forEach { otherCell ->
+            filter { otherCell -> otherCell != cell && otherCell.hasNoSelection() }.forEach { otherCell ->
                 otherCell.options.remove(cell.selection)
                 cleanupOptions(otherCell, false)
             }
+            filter { it.selection == null }
+                .flatMap { c -> c.options.map { o -> o to c } }
+                .groupBy { it.first }
+                .filter { it.value.size == 1 }
+                .forEach {
+                    val c = it.value.single().second
+                    c.selection = it.key
+                    cleanupOptions(c, true)
+                }
         }
     }
 
diff --git a/domain/src/main/kotlin/ch/dissem/yaep/domain/clues.kt b/domain/src/main/kotlin/ch/dissem/yaep/domain/clues.kt
index 41f5f11..fa75ffd 100644
--- a/domain/src/main/kotlin/ch/dissem/yaep/domain/clues.kt
+++ b/domain/src/main/kotlin/ch/dissem/yaep/domain/clues.kt
@@ -55,10 +55,9 @@ class NeighbourClue<A : ItemClass<A>, B : ItemClass<B>>(val a: Item<A>, val b: I
 
         for (iX in rowX.indices) {
             val cellX = rowX[iX]
-            if (cellX.options.contains(x)) {
+            if (cellX.mayBe(x, mayHaveSelection = false)) {
                 if (!rowY.getOrNull(iX - 1).mayBe(y) && !rowY.getOrNull(iX + 1).mayBe(y)) {
-                    cellX.options.remove(x)
-                    removed = true
+                    removed = cellX.options.remove(x) || removed
                 }
             }
         }
@@ -102,8 +101,11 @@ class OrderClue<L : ItemClass<L>, R : ItemClass<R>>(val left: Item<L>, val right
         var removed = false
         try {
             rowL.takeLast(rowL.size - lastR)
+                .filter { it.selection == null }
                 .forEach { removed = it.options.remove(left) || removed }
-            rowR.take(firstL + 1).forEach { removed = it.options.remove(right) || removed }
+            rowR.take(firstL + 1)
+                .filter { it.selection == null }
+                .forEach { removed = it.options.remove(right) || removed }
         } catch (e: IllegalArgumentException) {
             throw UnsolvablePuzzleException(e)
         }
@@ -274,11 +276,15 @@ class SameColumnClue<A : ItemClass<A>, B : ItemClass<B>>(val a: Item<A>, val b:
             val cellA = rowA[i]
             val cellB = rowB[i]
 
-            if (!cellA.mayBe(a)) {
-                removed = cellB.options.remove(b) || removed
+            if (cellB.hasNoSelection()) {
+                if (!cellA.mayBe(a)) {
+                    removed = cellB.options.remove(b) || removed
+                }
             }
-            if (!cellB.mayBe(b)) {
-                removed = cellA.options.remove(a) || removed
+            if (cellA.hasNoSelection()) {
+                if (!cellB.mayBe(b)) {
+                    removed = cellA.options.remove(a) || removed
+                }
             }
         }
         return removed
diff --git a/domain/src/test/kotlin/ch/dissem/yaep/domain/GameTest.kt b/domain/src/test/kotlin/ch/dissem/yaep/domain/GameTest.kt
index 93fbe81..4a0c647 100644
--- a/domain/src/test/kotlin/ch/dissem/yaep/domain/GameTest.kt
+++ b/domain/src/test/kotlin/ch/dissem/yaep/domain/GameTest.kt
@@ -29,6 +29,7 @@ class GameTest {
             val time = measureTime {
                 game = generateGame()
             }
+            println("Generated game #$i in ${time.inWholeMilliseconds}ms")
             expect(solve(game.grid, game.clues)).toEqual(SOLVABLE)
             expect(time).toBeLessThan(500.milliseconds)
             if (time < fastest) {