diff --git a/data/scenarios/Challenges/00-ORDER.txt b/data/scenarios/Challenges/00-ORDER.txt
index eb26f5eec..c1c1f6c3b 100644
--- a/data/scenarios/Challenges/00-ORDER.txt
+++ b/data/scenarios/Challenges/00-ORDER.txt
@@ -16,6 +16,7 @@ wave.yaml
 gallery.yaml
 wolf-goat-cabbage.yaml
 blender.yaml
+dna.yaml
 friend.yaml
 pack-tetrominoes.yaml
 dimsum.yaml
diff --git a/data/scenarios/Challenges/_dna/lab.sw b/data/scenarios/Challenges/_dna/lab.sw
new file mode 100644
index 000000000..6e7aa2d6b
--- /dev/null
+++ b/data/scenarios/Challenges/_dna/lab.sw
@@ -0,0 +1,177 @@
+def doN = \n. \f. if (n > 0) {f; doN (n - 1) f} {}; end;
+
+def getBaseForNumber = \n.
+    if (n == 0) {
+        "guanine";
+    } {
+        if (n == 1) {
+            "cytosine";
+        } {
+            if (n == 2) {
+                "adenine";
+            } {
+                "thymine";
+            };
+        };
+    };
+    end;
+
+def getNumberForBase = \n.
+    if (n == "guanine") {
+        0;
+    } {
+        if (n == "cytosine") {
+            1;
+        } {
+            if (n == "adenine") {
+                2;
+            } {
+                3;
+            };
+        };
+    };
+    end;
+
+/** Toggle the lowest bit */
+def getComplementNumber = \n.
+    if (n == 0) {
+        1;
+    } {
+        if (n == 1) {
+            0;
+        } {
+            if (n == 2) {
+                3;
+            } {
+                2;
+            };
+        };
+    };
+    end;
+
+def waitUntilSomethingExists =
+    maybeItemHere <- scan down;
+    case maybeItemHere (\_. 
+        watch down;
+        wait 1000;
+        waitUntilSomethingExists;
+    ) return;
+    end;
+
+def waitUntilHere = \item.
+    hereNow <- ishere item;
+    if hereNow {} {
+        watch down;
+        wait 1000;
+        waitUntilHere item;
+    };
+    end;
+
+def waitUntilOccupied =
+    stillEmpty <- isempty;
+    if stillEmpty {
+        watch down;
+        wait 1000;
+        waitUntilOccupied;
+    } {};
+    end;
+
+def myStandby = \receptacleLoc.
+    teleport self receptacleLoc;
+    entToClone <- grab;
+    teleport self (36, -11);
+    turn back;
+    return $ inR entToClone;
+    end;
+
+def placeBase = \standbyFunc. \n. 
+
+    if (n > 0) {
+        idx <- random 4;
+        let entTemp = getBaseForNumber idx in
+        let ent = entTemp in
+        create ent;
+        place ent;
+        move;
+
+        clonedOrganism <- placeBase standbyFunc $ n - 1;
+
+        // Unwinds the stack; verifies the original placement order
+        placedEnt <- instant waitUntilSomethingExists;
+        let isGood = ent == placedEnt in
+        move;
+
+        if isGood {
+            return clonedOrganism;
+        } {
+            return $ inL ();
+        }
+    } {
+        // Returns the clonedOrganism
+        standbyFunc;
+    };
+    end;
+
+def makeDnaStrand = \receptacleLoc.
+    teleport self (5, -2);
+
+    dims <- floorplan "DNA decoder";
+    let decoderWidth = fst dims in
+    eitherClonedOrganism <- placeBase (myStandby receptacleLoc) decoderWidth;
+
+    case eitherClonedOrganism (\_.
+        create "pixel (R)";
+    ) (\clonedItem.
+        instant $ (
+            teleport self (0, -11);
+            waitUntilHere "switch (on)";
+
+            bottomWaypointQuery <- waypoint "receiver" 1;
+            let receptacleLoc2 = snd bottomWaypointQuery in
+            teleport self receptacleLoc2;
+
+            sow clonedItem;
+            create clonedItem;
+            k <- robotnamed "keeper";
+            give k clonedItem;
+
+            let slideBox = "slide box" in
+            create slideBox;
+            give base slideBox;
+            say $ "You got a new \"" ++ slideBox ++ "\"";
+        );
+    );
+    end;
+
+def waitForCloneableOrganism =
+
+    waypointQuery <- waypoint "receiver" 0;
+    let receptacleLoc = snd waypointQuery in
+    organism <- instant (
+        teleport self receptacleLoc;
+
+        waitUntilOccupied;
+
+        thingHere <- scan down;
+        case thingHere (\x. return $ inL x) (\item.
+            isOrganism <- hastag item "organism";
+            return $ inR item;
+        );
+    );
+
+    case organism (\_.
+        say "Not a cloneable organism!";
+        waitForCloneableOrganism;
+    ) (\item.
+        create "pixel (G)";
+        makeDnaStrand receptacleLoc;
+    );
+    end;
+
+def go =
+    waitForCloneableOrganism;
+    turn east;
+    go;
+    end;
+
+go;
diff --git a/data/scenarios/Challenges/_dna/mirrorbot.sw b/data/scenarios/Challenges/_dna/mirrorbot.sw
new file mode 100644
index 000000000..c9ce6abef
--- /dev/null
+++ b/data/scenarios/Challenges/_dna/mirrorbot.sw
@@ -0,0 +1,99 @@
+def doN = \n. \f. if (n > 0) {f; doN (n - 1) f} {}; end;
+
+def getBaseForNumber = \n.
+    if (n == 0) {
+        "guanine";
+    } {
+        if (n == 1) {
+            "cytosine";
+        } {
+            if (n == 2) {
+                "adenine";
+            } {
+                "thymine";
+            };
+        };
+    };
+    end;
+
+def getNumberForBase = \n.
+    if (n == "guanine") {
+        0;
+    } {
+        if (n == "cytosine") {
+            1;
+        } {
+            if (n == "adenine") {
+                2;
+            } {
+                if (n == "thymine") {
+                    3;
+                } {-1};
+            };
+        };
+    };
+    end;
+
+/** Toggle the lowest bit */
+def getComplementNumber = \n.
+    if (n == 0) {
+        1;
+    } {
+        if (n == 1) {
+            0;
+        } {
+            if (n == 2) {
+                3;
+            } {
+                2;
+            };
+        };
+    };
+    end;
+
+def placeComplementOf = \item.
+    let baseNumber = getNumberForBase item in
+    if (baseNumber >= 0) {
+        let complementNumber = getComplementNumber baseNumber in
+        let newItem = getBaseForNumber complementNumber in
+        move;
+        create newItem;
+        place newItem;
+    } {
+        let sludge = "organic sludge" in
+        create sludge;
+        place sludge;
+    }
+    end;
+
+def waitUntilHere =
+    watch down;
+    wait 1000;
+
+    maybeItemDown <- scan down;
+    case maybeItemDown (\_. waitUntilHere) (\itemHere.
+        placeComplementOf itemHere;
+    );
+    end;
+
+def waitUntilEmpty =
+    watch down;
+    wait 1000;
+    emptyHere <- isempty;
+    if emptyHere {
+        // reset the position
+        turn back;
+        move;
+        turn back;
+    } {
+        waitUntilEmpty;
+    }
+    end;
+
+def go =
+    instant waitUntilHere;
+    waitUntilEmpty;
+    go;
+    end;
+
+go;
diff --git a/data/scenarios/Challenges/_dna/resetter.sw b/data/scenarios/Challenges/_dna/resetter.sw
new file mode 100644
index 000000000..a88379175
--- /dev/null
+++ b/data/scenarios/Challenges/_dna/resetter.sw
@@ -0,0 +1,48 @@
+def doN = \n. \f. if (n > 0) {f; doN (n - 1) f} {}; end;
+
+/**
+Assumes we are on the left edge of a row of nucleobases
+*/
+def resetPlayfieldRow =
+    dims <- floorplan "DNA decoder";
+    let decoderWidth = fst dims in
+    doN decoderWidth (grab; move;);
+    end;
+
+def resetPlayfield =
+    teleport self (5, -2);
+    resetPlayfieldRow;
+    teleport self (5, -3);
+    resetPlayfieldRow;
+
+    teleport self (5, -11);
+    resetPlayfieldRow;
+    teleport self (5, -12);
+    resetPlayfieldRow;
+    end;
+
+def watchSwitch = \lastState.
+    watch down;
+    wait 1000;
+    found <- scan down;
+    case found return (\item.
+        if (item != lastState) {
+            if (item == "switch (off)") {
+                loc <- whereami;
+                resetPlayfield;
+                teleport self loc;
+            } {
+            };
+        } {};
+        watchSwitch item;
+    );
+    end;
+
+def go =
+    instant $ (
+        found <- scan down;
+        case found return watchSwitch;
+    );
+    end;
+
+go;
diff --git a/data/scenarios/Challenges/_dna/solution.sw b/data/scenarios/Challenges/_dna/solution.sw
new file mode 100644
index 000000000..d63f598b3
--- /dev/null
+++ b/data/scenarios/Challenges/_dna/solution.sw
@@ -0,0 +1,262 @@
+def doN = \n. \f. if (n > 0) {f; doN (n - 1) f} {}; end;
+
+def moveUntilBlocked =
+    blockedHere <- blocked;
+    if blockedHere {} {
+        move;
+        moveUntilBlocked;
+    }
+    end;
+
+def getBaseForNumber = \n.
+    if (n == 0) {
+        "guanine";
+    } {
+        if (n == 1) {
+            "cytosine";
+        } {
+            if (n == 2) {
+                "adenine";
+            } {
+                "thymine";
+            };
+        };
+    };
+    end;
+
+def getNumberForBase = \n.
+    if (n == "guanine") {
+        0;
+    } {
+        if (n == "cytosine") {
+            1;
+        } {
+            if (n == "adenine") {
+                2;
+            } {
+                3;
+            };
+        };
+    };
+    end;
+
+/** Toggle the lowest bit */
+def getComplementNumber = \n.
+    if (n == 0) {
+        1;
+    } {
+        if (n == 1) {
+            0;
+        } {
+            if (n == 2) {
+                3;
+            } {
+                2;
+            };
+        };
+    };
+    end;
+
+def waitWhileHere = \item.
+    stillHere <- ishere item;
+    if stillHere {
+        watch down;
+        wait 1000;
+        waitWhileHere item;
+    } {};
+    end;
+
+def waitUntilHere = \item.
+    hereNow <- ishere item;
+    if hereNow {} {
+        watch down;
+        wait 1000;
+        waitUntilHere item;
+    };
+    end;
+
+def moveToPattern =
+    turn back;
+    doN 5 move;
+    turn left;
+    doN 4 move;
+    turn left;
+    move;
+    end;
+
+def moveToOtherRow =
+    turn right;
+    doN 2 move;
+    turn right;
+    doN 4 move;
+    turn left;
+    doN 4 move;
+    turn left;
+    doN 4 move;
+    turn right;
+    doN 2 move;
+    turn right;
+    move;
+    end;
+
+def waitForItem : Dir -> Cmd Text = \d.
+    item <- scan d;
+    case item (\_. 
+        watch d;
+        wait 1000;
+        waitForItem d;
+    ) return;
+    end;
+
+def waitForSpecificItem = \item. \d.
+    itemIsHere <- ishere item;
+    if itemIsHere {
+    } {
+        watch d;
+        wait 1000;
+        waitForSpecificItem item d;
+    }
+    end;
+
+def placeComplementOf = \item.
+    let baseNumber = getNumberForBase item in
+    let complementNumber = getComplementNumber baseNumber in
+    let newItem = getBaseForNumber complementNumber in
+    place newItem;
+    end;
+
+/**
+Store the observed entities in the recursion stack.
+*/
+def replicatePattern = \standbyFunc. \n.
+    if (n > 0) {
+        thingTemp <- waitForItem left;
+        let thing = thingTemp in
+        placeComplementOf thing;
+        move;
+        replicatePattern standbyFunc $ n - 1;
+
+        place thing;
+        move;
+    } {
+        standbyFunc;
+    }
+    end;
+
+/**
+Position self at entrance
+*/
+def pickFlowerAndWater =
+    doN 6 move;
+    dahlia <- grab;
+
+    turn left;
+    doN 8 move;
+    turn right;
+    doN 31 move;
+    clover <- grab;
+    turn back;
+    doN 35 move;
+    d <- grab;
+    doN 10 move;
+
+    turn left;
+
+    doN 18 move;
+    use "siphon" forward;
+    turn left;
+    doN 7 (
+        move;
+        use "siphon" right;
+    );
+    doN 4 move;
+    turn right;
+    doN 16 move;
+
+    mushroom <- grab;
+
+    turn back;
+    doN 23 move;
+    
+    turn right;
+    return dahlia;
+    
+    // return mushroom;
+    // return d;
+    end;
+
+
+def waitUntilOccupied =
+    stillEmpty <- isempty;
+    if stillEmpty {
+        watch down;
+        wait 1000;
+        waitUntilOccupied;
+    } {};
+    end;
+
+def returnToInputReceptacle =
+    turn back;
+    doN 5 move;
+    turn left;
+    moveUntilBlocked;
+    turn left;
+    doN 29 move;
+    turn right;
+    moveUntilBlocked;
+    turn left;
+    doN 4 move;
+    turn right;
+    doN 6 move;
+    turn right;
+    moveUntilBlocked;
+    end;
+
+def completeDnaTask = \sentinel.
+    place sentinel;
+    make "specimen slide";
+
+    doN 16 $ make "cytosine";
+
+    waitWhileHere sentinel;
+    moveToPattern;
+    replicatePattern moveToOtherRow 32;
+    
+    // Activate the switch
+    doN 3 move;
+    drill forward;
+    wait 2;
+    drill forward;
+
+    turn left;
+    doN 6 move;
+    turn left;
+    doN 32 move;
+    turn left;
+    doN 2 move;
+    turn left;
+    move;
+
+    waitUntilOccupied;
+    grab;
+
+    returnToInputReceptacle;
+    end;
+
+def iterateOrganisms = \idx.
+    result <- tagmembers "organism" idx;
+    let totalCount = fst result in
+    if (idx < totalCount) {
+        completeDnaTask $ snd result;
+        iterateOrganisms $ idx + 1;
+    } {};
+    end;
+
+def go =
+    _sentinel <- pickFlowerAndWater;
+    moveUntilBlocked;
+
+    iterateOrganisms 0;
+    end;
+
+go;
diff --git a/data/scenarios/Challenges/_dna/topchecker.sw b/data/scenarios/Challenges/_dna/topchecker.sw
new file mode 100644
index 000000000..abb4b63da
--- /dev/null
+++ b/data/scenarios/Challenges/_dna/topchecker.sw
@@ -0,0 +1,107 @@
+def doN = \n. \f. if (n > 0) {f; doN (n - 1) f} {}; end;
+
+def getBaseForNumber = \n.
+    if (n == 0) {
+        "guanine";
+    } {
+        if (n == 1) {
+            "cytosine";
+        } {
+            if (n == 2) {
+                "adenine";
+            } {
+                "thymine";
+            };
+        };
+    };
+    end;
+
+def getNumberForBase = \n.
+    if (n == "guanine") {
+        0;
+    } {
+        if (n == "cytosine") {
+            1;
+        } {
+            if (n == "adenine") {
+                2;
+            } {
+                if (n == "thymine") {
+                    3;
+                } {-1};
+            };
+        };
+    };
+    end;
+
+/** Toggle the lowest bit */
+def getComplementNumber = \n.
+    if (n == 0) {
+        1;
+    } {
+        if (n == 1) {
+            0;
+        } {
+            if (n == 2) {
+                3;
+            } {
+                2;
+            };
+        };
+    };
+    end;
+
+def waitUntilHere = \remainingCount.
+    if (remainingCount > 0) {
+        maybeItemHere <- scan down;
+        case maybeItemHere (\_. 
+            watch down;
+            wait 1000;
+            waitUntilHere remainingCount;
+        ) (\itemHere.
+
+            maybeItemAbove <- scan left;
+            case maybeItemAbove (\_. fail "Expected an item here.") (\itemAbove.
+                let num = getNumberForBase itemAbove in
+                if (num >= 0) {
+                    let complementNum = getComplementNumber num in
+                    let complementItem = getBaseForNumber complementNum in
+                    if (complementItem == itemHere) {
+                        move;
+                        waitUntilHere $ remainingCount - 1;
+                    } {
+                        create "pixel (R)";
+                    }
+                } {
+                    fail "Expected nonnegative item index."
+                }
+            );
+        );
+    } {
+        create "pixel (G)";
+    };
+    end;
+
+def waitUntilEmpty =
+    watch down;
+    wait 1000;
+    emptyHere <- isempty;
+    if emptyHere {} {
+        waitUntilEmpty;
+    }
+    end;
+
+def waitForReset =
+    backup;
+    waitUntilEmpty;
+    end;
+
+def go = \startingLoc.
+    instant $ waitUntilHere 32;
+    waitForReset;
+    teleport self startingLoc;
+    go startingLoc;
+    end;
+
+loc <- whereami;
+go loc;
diff --git a/data/scenarios/Challenges/dna.yaml b/data/scenarios/Challenges/dna.yaml
new file mode 100644
index 000000000..369510ff4
--- /dev/null
+++ b/data/scenarios/Challenges/dna.yaml
@@ -0,0 +1,593 @@
+version: 1
+name: DNA
+author: Karl Ostmo
+description: |
+  Copy strands of DNA in the lab to replicate organisms
+creative: false
+seed: 9
+attrs:
+  - name: floorattr
+    bg: "#111111"
+  - name: wall2
+    fg: "#88ee22"
+  - name: pink
+    fg: "#ff99bb"
+  - name: lemon
+    fg: "#eeee99"
+  - name: clover
+    bg: "#225522"
+  - name: beige
+    fg: "#f5f5dc"
+  - name: soup
+    fg: "#338822"
+    bg: "#774422"
+terrains:
+  - name: floor
+    attr: floorattr
+    description: |
+      Laboratory floor
+objectives:
+  - id: place_flower
+    teaser: Place subject
+    goal:
+      - |
+        The laboratory building ahead is neatly landscaped, though
+        its decorative `pond`{=structure} exudes a peculiar quality.
+        There may be a device you can `use` to sample its contents.
+
+        The DNA lab has two large apparatus inside.
+        The first is a `DNA sequencer`{=structure} that
+        determines the arrangement of ATCG pairs within an `organism`{=tag}'s genome.
+
+        The `DNA decoder`{=structure} in the lab's south wing can reconstitute
+        an `organism`{=tag} from its genome.
+
+        To get started, borrow a `dahlia`{=entity} from the flowerbed at the lab
+        entrance and place it in the receptacle directly to your east.
+    condition: |
+      r <- robotnamed "lab";
+      as r {
+        has "pixel (G)";
+      }
+  - id: place_complements
+    teaser: Complement strand
+    prerequisite: place_flower
+    goal:
+      - |
+        The `DNA sequencer`{=structure} will begin to decode the subject's DNA.
+        The subject will be dematerialized once the top row
+        of the "double helix" has been decoded.
+
+        You must then complete the double helix (fill in the second row within the device)
+        with complementary base pairs.
+        Use your `soup strainer`{=entity} to obtain ingredients.
+        Consult your *Compendium* for appropriate pairings.
+
+        Note that `scan`ning has a cost, and you have a limited supply of
+        `specimen slide`{=entity}s (in a `slide box`{=entity}) with which to
+        `scan` DNA bases using your `microscope`{=entity}.
+    condition: |
+      r <- robotnamed "topchecker";
+      as r {
+        has "pixel (G)";
+      }
+  - id: create_clone
+    prerequisite: place_complements
+    teaser: Create clone
+    goal:
+      - |
+        Now let's make a clone! Recreate the top half of the
+        DNA strand in the south wing's `DNA decoder`{=structure}
+        (you remember the sequence, right?).
+
+        Each element you `place` will be automatically complemented.
+
+        When all segments are placed, `drill` the switch on the western wall to
+        commence rematerialization. `grab` the clone (once matured) as a souvenir!
+    condition: |
+      def checkMember = \idx.
+        result <- tagmembers "organism" idx;
+        let totalCount = fst result in
+        hasThis <- has $ snd result;
+        if hasThis {
+          return true;
+        } {
+          if (idx < totalCount - 1) {
+            checkMember $ idx + 1;
+          } {
+            return false;
+          }
+        };
+        end;
+
+      k <- robotnamed "keeper";
+      as k {
+        checkMember 0;
+      }
+  - prerequisite: create_clone
+    teaser: More clones
+    goal:
+      - |
+        Toggle the switch off to reset the lab.
+      - |
+        Find three more different `organism`{=tag}s to clone.
+        Explore outside nearby the lab for specimens.
+    condition: |
+      def countMembers = \memberCount. \idx.
+        result <- tagmembers "organism" idx;
+        let totalCount = fst result in
+
+        if (idx < totalCount) {
+          hasThis <- has $ snd result;
+          let memberCountAddition = if hasThis {1} {0} in
+          countMembers (memberCount + memberCountAddition) $ idx + 1;
+        } {
+          return memberCount;
+        }
+        end;
+
+      k <- robotnamed "keeper";
+      as k {
+        c <- countMembers 0 0;
+        return $ c >= 4;
+      }
+robots:
+  - name: base
+    dir: east
+    loc: [-8, 4]
+    devices:
+      - antenna
+      - ADT calculator
+      - barcode reader
+      - branch predictor
+      - comparator
+      - compass
+      - dictionary
+      - feeler
+      - grabber
+      - hearing aid
+      - lambda
+      - logger
+      - microscope
+      - rolex
+      - siphon
+      - soup strainer
+      - strange loop
+      - switch puller
+      - treads
+      - welder
+      - workbench
+    inventory:
+      - [1, slide box]
+  - name: lab
+    system: true
+    dir: east
+    display:
+      invisible: true
+      attr: 'robot'
+    devices:
+      - switch puller
+    inventory:
+      - [1, branch predictor]
+      - [1, treads]
+      - [1, beaglepuss]
+      - [1, antenna]
+      - [1, comparator]
+      - [1, clock]
+      - [1, workbench]
+      - [1, grabber]
+      - [1, ADT calculator]
+      - [1, dictionary]
+      - [1, lambda]
+      - [1, logger]
+      - [1, welder]
+      - [1, hearing aid]
+      - [1, scanner]
+      - [1, strange loop]
+      - [1, solar panel]
+    program: |
+      run "data/scenarios/Challenges/_dna/lab.sw"
+  - name: topchecker
+    system: true
+    dir: east
+    display:
+      invisible: true
+      attr: 'robot'
+    program: |
+      run "data/scenarios/Challenges/_dna/topchecker.sw"
+  - name: mirrorbot
+    system: true
+    dir: south
+    display:
+      invisible: true
+      attr: 'robot'
+    program: |
+      run "data/scenarios/Challenges/_dna/mirrorbot.sw"
+  - name: resetter
+    description: resets the apparatus after completion by watching the switch
+    system: true
+    dir: east
+    display:
+      invisible: true
+      attr: 'robot'
+    program: |
+      run "data/scenarios/Challenges/_dna/resetter.sw"
+  - name: keeper
+    description: keeps track of cloned specimens
+    system: true
+    dir: south
+    display:
+      invisible: true
+      attr: 'robot'
+solution: |
+  run "data/scenarios/Challenges/_dna/solution.sw"
+structures:
+  - name: pond
+    recognize:
+      - north
+    structure:
+      mask: '.'
+      palette:
+        'x': [grass, rock]
+        'w': [dirt, pond broth]
+      map: |
+        ...xxxxxxxx..
+        ..xwwwwwwwwx.
+        ..xwwwwwwwwwx
+        ..xwwwwwwwwwx
+        .xwwwwwwxxxx.
+        xwwwwwwx.....
+        xwwwwwwx.....
+        .xxxxxx......
+  - name: fairy ring
+    structure:
+      mask: '.'
+      palette:
+        'm': [grass, mushroom]
+      map: |
+        ....mm.m...
+        ..m........
+        .........m.
+        ..m........
+        ...m...m...
+  - name: receptacle
+    structure:
+      mask: '.'
+      palette:
+        'x': [floor, wall]
+        'w': [floor, wall2]
+        'f':
+          cell: [floor, erase]
+          waypoint:
+            name: receiver
+      map: |
+        ww........
+        fwxxxxxxxx
+        ww.x.x.x.x
+  - name: decoder base
+    structure:
+      palette:
+        '┬': [stone, down and horizontal wall]
+        '┴': [stone, up and horizontal wall]
+        ':': [floor, erase]
+      map: |
+        ┬┬┬┬┬┬┬┬┬┬┬┬┬┬┬┬┬┬┬┬┬┬┬┬┬┬┬┬┬┬┬┬
+        ::::::::::::::::::::::::::::::::
+        ::::::::::::::::::::::::::::::::
+        ┴┴┴┴┴┴┴┴┴┴┴┴┴┴┴┴┴┴┴┴┴┴┴┴┴┴┴┴┴┴┴┴
+  - name: copybots overlay
+    structure:
+      mask: '.'
+      palette:
+        'm': [floor, erase, mirrorbot]
+      map: |
+        ................................
+        mmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm
+        ................................
+        ................................
+  - name: decoder overlay
+    structure:
+      mask: '.'
+      palette:
+        'c': [floor, erase, topchecker]
+      map: |
+        ................................
+        ................................
+        c...............................
+        ................................
+  - name: DNA decoder
+    recognize:
+      - north
+    structure:
+      placements:
+        - src: decoder base
+        - src: copybots overlay
+        - src: receptacle
+          offset: [18, -4]
+          orient:
+            up: south
+      map: ""
+  - name: DNA sequencer
+    recognize:
+      - north
+    structure:
+      placements:
+        - src: decoder base
+        - src: decoder overlay
+        - src: receptacle
+          offset: [4, 3]
+      map: ""
+entities:
+  - name: barcode reader
+    display:
+      attr: red
+      char: 'S'
+    description:
+      - Reads the 'tag' of an item
+    properties: [pickable]
+    capabilities: [hastag, tagmembers]
+  - name: dahlia
+    display:
+      char: '*'
+      attr: pink
+    description:
+      - Brightly colored flower
+    properties: [known, pickable, growable]
+    growth:
+      duration: [20, 30]
+    tags: [organism]
+  - name: daisy
+    display:
+      char: 'x'
+      attr: lemon
+    description:
+      - Pretty flower
+    properties: [pickable, growable]
+    growth:
+      duration: [15, 30]
+    tags: [organism]
+  - name: clover
+    display:
+      char: 'c'
+      attr: clover
+    description:
+      - A tiny, 3-leaf plant
+    properties: [pickable, growable]
+    growth:
+      duration: [10, 20]
+    tags: [organism]
+  - name: mushroom
+    display:
+      char: 'm'
+      attr: beige
+    description:
+      - Invasive fungus
+    properties: [pickable, growable]
+    growth:
+      duration: [15, 25]
+      spread:
+        radius: 2
+        density: 0.5
+    biomes: [floor, stone]
+    tags: [organism]
+  - name: wall2
+    display:
+      char: 'w'
+      attr: wall2
+    description:
+      - Just a wall
+    properties: [known, unwalkable, boundary]
+  - name: primordial soup
+    display:
+      char: 's'
+      attr: soup
+    description:
+      - Can be decomposed into nucleic acids
+    properties: [pickable, liquid]
+  - name: pond broth
+    display:
+      char: 's'
+      attr: soup
+    description:
+      - Can be decomposed into nucleic acids
+    properties: [pickable, liquid]
+  - name: soup strainer
+    display:
+      char: 'r'
+    description:
+      - Extracts nucleic acids from `primordial soup`{=entity}
+    properties: [known, pickable]
+  - name: feeler
+    display:
+      char: 'm'
+    description:
+      - Senses presence of specific entities
+    properties: [known, pickable]
+    capabilities: [blocked, ishere, isempty]
+  - name: microscope
+    display:
+      char: 'm'
+    description:
+      - Scan for the cost of 1 `specimen slide`{=entity}
+    properties: [known, pickable]
+    capabilities:
+      - capability: scan
+        cost:
+          - [1, "specimen slide"]
+  - name: specimen slide
+    display:
+      char: 'i'
+      attr: device
+    description:
+      - Can take a sample of DNA for scanning
+  - name: slide box
+    display:
+      char: 'b'
+      attr: device
+    description:
+      - Contains `specimen slides`{=entity}
+  - name: guanine
+    display:
+      char: 'G'
+      attr: red
+    description:
+      - One of the four nucleobases in DNA.
+      - Is paired with `cytosine`{=entity}.
+    properties: [known]
+  - name: cytosine
+    display:
+      char: 'C'
+      attr: blue
+    description:
+      - One of the four nucleobases in DNA.
+      - Is paired with `guanine`{=entity}.
+    properties: [known]
+  - name: adenine
+    display:
+      char: 'A'
+      attr: green
+    description:
+      - One of the four nucleobases in DNA.
+      - Is paired with `thymine`{=entity}.
+    properties: [known]
+  - name: thymine
+    display:
+      char: 'T'
+      attr: gold
+    description:
+      - One of the four nucleobases in DNA.
+      - Is paired with `adenine`{=entity}.
+    properties: [known]
+  - name: switch (off)
+    display:
+      attr: red
+      char: '•'
+    description:
+      - A control in the deactivated position.
+    properties: [known]
+  - name: switch (on)
+    display:
+      attr: green
+      char: '•'
+    description:
+      - A control in the activated position.
+    properties: [known]
+  - name: organic sludge
+    display:
+      attr: green
+      char: 'S'
+    description:
+      - A repulsive, shuddering mass of slime.
+    properties: [pickable]
+  - name: switch puller
+    display:
+      char: 'P'
+      attr: gold
+    capabilities: [drill]
+    description:
+      - Can pull switches
+  - name: siphon
+    display:
+      char: 's'
+      attr: device
+    capabilities: [drill]
+    description:
+      - Can retrieve liquid
+recipes:
+  - in:
+      - [1, slide box]
+    out:
+      - [32, specimen slide]
+  - in:
+      - [1, primordial soup]
+    out:
+      - [4, cytosine]
+      - [4, guanine]
+      - [4, adenine]
+      - [4, thymine]
+    required:
+      - [1, soup strainer]
+  - in:
+      - [1, switch (off)]
+    out:
+      - [1, switch (on)]
+    required:
+      - [1, switch puller]
+  - in:
+      - [1, switch (on)]
+    out:
+      - [1, switch (off)]
+    required:
+      - [1, switch puller]
+  - in:
+      - [1, pond broth]
+    out:
+      - [8, primordial soup]
+    required:
+      - [1, siphon]
+known: [flower, rock]
+world:
+  dsl: |
+    let
+      flowerNoise = perlin seed 1 0.15 0.0,
+      soupNoise = perlin seed 2 0.04 1.0,
+
+      flowers = flowerNoise > 0.70,
+      soup = soupNoise > 0.9
+    in
+      overlay
+      [ {grass}
+      , mask (flowers && (x - y) % 3 == 0) {daisy}
+      , mask soup {clover}
+      ]
+  upperleft: [-2, 4]
+  mask: 'q'
+  palette:
+    'z': [stone, wall]
+    '.': [stone, erase]
+    'G':
+      cell: [stone, erase]
+    'o': [stone, erase]
+    'd': [dirt, dahlia]
+    'v': [stone, erase, lab, keeper]
+    '0':
+      cell: [stone, switch (off), resetter]
+      waypoint:
+        name: switch
+    'D':
+      structure:
+        name: DNA decoder
+      cell: [floor, erase]
+    'E':
+      structure:
+        name: DNA sequencer
+      cell: [floor, erase]
+  placements:
+    - src: pond
+      offset: [-17, -10]
+    - src: fairy ring
+      offset: [-5, -25]
+  map: |
+    dzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz
+    dzv.........................................z
+    zzz........oo...............................z
+    ............o...............................z
+    zzz........oo...............................z
+    dz.....Eooooooooooooooooooooooooooooooo.....z
+    dz.....o..............................o.....z
+    dz.....o..............................o.....z
+    dz.....oooooooooooooooooooooooooooooooo.....z
+    qz..........................................z
+    qzzzzzzzzz.zzzzzzzzzzzzzzzzzzzzzzzz.zzzzzzzzz
+    qqqqqqqqqzGzqqqqqqqqqqqqqqqqqqqqqqzGzqqqqqqqq
+    qzzzzzzzzz.zzzzzzzzzzzzzzzzzzzzzzzz.zzzzzzzzz
+    qz..........................................z
+    qzz....D....................................z
+    qz0.........................................z
+    qzz.........................................z
+    qz..........................................z
+    qz..........................................z
+    qz..........................................z
+    qz..........................................z
+    qz..........................................z
+    qzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz
diff --git a/src/swarm-doc/Swarm/Doc/Wiki/Cheatsheet.hs b/src/swarm-doc/Swarm/Doc/Wiki/Cheatsheet.hs
index 68265bd54..61feb18ad 100644
--- a/src/swarm-doc/Swarm/Doc/Wiki/Cheatsheet.hs
+++ b/src/swarm-doc/Swarm/Doc/Wiki/Cheatsheet.hs
@@ -42,7 +42,7 @@ import Swarm.Language.Syntax qualified as Syntax
 import Swarm.Language.Text.Markdown as Markdown (docToMark)
 import Swarm.Language.Typecheck (inferConst)
 import Swarm.Pretty (prettyText, prettyTextLine)
-import Swarm.Util (maximum0, showT)
+import Swarm.Util (applyWhen, maximum0, showT)
 
 -- * Types
 
@@ -170,10 +170,7 @@ capabilityRow PageAddress {..} em cap =
       then t
       else addLink (entityAddress <> "#" <> T.replace " " "-" t) t
   linkCommand c =
-    ( if T.null commandsAddress
-        then id
-        else addLink (commandsAddress <> "#" <> showT c)
-    )
+    applyWhen (not $ T.null commandsAddress) (addLink $ commandsAddress <> "#" <> showT c)
       . codeQuote
       $ constSyntax c
 
diff --git a/src/swarm-engine/Swarm/Game/State.hs b/src/swarm-engine/Swarm/Game/State.hs
index d02dcf40e..5c1df4d5e 100644
--- a/src/swarm-engine/Swarm/Game/State.hs
+++ b/src/swarm-engine/Swarm/Game/State.hs
@@ -120,7 +120,7 @@ import Swarm.Language.Pipeline (processTermEither)
 import Swarm.Language.Syntax (SrcLoc (..), TSyntax, sLoc)
 import Swarm.Language.Value (Env)
 import Swarm.Log
-import Swarm.Util (uniq)
+import Swarm.Util (applyWhen, uniq)
 import Swarm.Util.Lens (makeLensesNoSigs)
 
 newtype Sha1 = Sha1 String
@@ -294,7 +294,7 @@ messageNotifications = to getNotif
     new = takeWhile (\l -> l ^. leTime > gs ^. messageInfo . lastSeenMessageTime) $ reverse allUniq
     -- creative players and system robots just see all messages (and focused robots logs)
     unchecked = gs ^. creativeMode || fromMaybe False (focusedRobot gs ^? _Just . systemRobot)
-    messages = (if unchecked then id else focusedOrLatestClose) (gs ^. messageInfo . messageQueue)
+    messages = applyWhen (not unchecked) focusedOrLatestClose (gs ^. messageInfo . messageQueue)
     allMessages = Seq.sort $ focusedLogs <> messages
     focusedLogs = maybe Empty (view robotLog) (focusedRobot gs)
     -- classic players only get to see messages that they said and a one message that they just heard
@@ -332,7 +332,7 @@ recalcViewCenterAndRedraw :: GameState -> GameState
 recalcViewCenterAndRedraw g =
   g
     & robotInfo .~ newRobotInfo
-    & (if ((/=) `on` (^. viewCenter)) oldRobotInfo newRobotInfo then needsRedraw .~ True else id)
+    & applyWhen (((/=) `on` (^. viewCenter)) oldRobotInfo newRobotInfo) (needsRedraw .~ True)
  where
   oldRobotInfo = g ^. robotInfo
   newRobotInfo = recalcViewCenter oldRobotInfo
diff --git a/src/swarm-engine/Swarm/Game/Step/Const.hs b/src/swarm-engine/Swarm/Game/Step/Const.hs
index 1c62d0ad0..74b336f13 100644
--- a/src/swarm-engine/Swarm/Game/Step/Const.hs
+++ b/src/swarm-engine/Swarm/Game/Step/Const.hs
@@ -1415,7 +1415,7 @@ execConst runChildProg c vs s k = do
         return $ Out v s k
       else do
         time <- use $ temporal . ticks
-        return . (if remTime <= 1 then id else Waiting (addTicks (fromIntegral remTime) time)) $
+        return . applyWhen (remTime > 1) (Waiting (addTicks (fromIntegral remTime) time)) $
           Out v s (FImmediate c wf rf : k)
    where
     remTime = r ^. recipeTime
diff --git a/src/swarm-engine/Swarm/Game/Step/Util/Command.hs b/src/swarm-engine/Swarm/Game/Step/Util/Command.hs
index a6dd19d87..037cb008c 100644
--- a/src/swarm-engine/Swarm/Game/Step/Util/Command.hs
+++ b/src/swarm-engine/Swarm/Game/Step/Util/Command.hs
@@ -63,6 +63,7 @@ import Swarm.Language.Requirements.Type qualified as R
 import Swarm.Language.Syntax
 import Swarm.Language.Text.Markdown qualified as Markdown
 import Swarm.Log
+import Swarm.Util (applyWhen)
 import System.Clock (TimeSpec)
 import Prelude hiding (Applicative (..), lookup)
 
@@ -156,9 +157,8 @@ purgeFarAwayWatches = do
 
   let isNearby = isNearbyOrExempt privileged myLoc
       f loc =
-        if not $ isNearby loc
-          then IS.delete rid
-          else id
+        applyWhen (not $ isNearby loc) $
+          IS.delete rid
 
   robotInfo . robotsWatching %= M.filter (not . IS.null) . M.mapWithKey f
 
diff --git a/src/swarm-lang/Swarm/Language/LSP/Hover.hs b/src/swarm-lang/Swarm/Language/LSP/Hover.hs
index 6a62b9bee..c2c1a9f29 100644
--- a/src/swarm-lang/Swarm/Language/LSP/Hover.hs
+++ b/src/swarm-lang/Swarm/Language/LSP/Hover.hs
@@ -242,7 +242,7 @@ explain trm = case trm ^. sTerm of
   internal description = literal $ description <> "\n**These should never show up in surface syntax.**"
   constGenSig c =
     let ity = inferConst c
-     in if ty `eq` ity then id else typeSignature (prettyText c) ity
+     in U.applyWhen (not $ ty `eq` ity) $ typeSignature (prettyText c) ity
 
 -- | Helper function to explain function application.
 --
diff --git a/src/swarm-lang/Swarm/Language/Requirements/Analysis.hs b/src/swarm-lang/Swarm/Language/Requirements/Analysis.hs
index 89a03c455..b04d4e35b 100644
--- a/src/swarm-lang/Swarm/Language/Requirements/Analysis.hs
+++ b/src/swarm-lang/Swarm/Language/Requirements/Analysis.hs
@@ -26,6 +26,7 @@ import Swarm.Language.Requirements.Type
 import Swarm.Language.Syntax
 import Swarm.Language.Syntax.Direction (isCardinal)
 import Swarm.Language.Types
+import Swarm.Util (applyWhen)
 
 -- | Infer the requirements to execute/evaluate a term in a given
 --   context.
@@ -122,8 +123,8 @@ requirements tdCtx ctx =
       localReqCtx <- ask @ReqCtx
       localTDCtx <- ask @TDCtx
       let bodyReqs =
-            (if r then (singletonCap CRecursion <>) else id)
-              (requirements localTDCtx localReqCtx t1)
+            applyWhen r (singletonCap CRecursion <>) $
+              requirements localTDCtx localReqCtx t1
       local @ReqCtx (Ctx.addBinding x bodyReqs) $ go t2
     -- Using tydef requires CEnv, plus whatever the requirements are
     -- for the type itself.
diff --git a/src/swarm-topography/Swarm/Game/Scenario/Topography/Placement.hs b/src/swarm-topography/Swarm/Game/Scenario/Topography/Placement.hs
index d6f77a94b..0026a1ac6 100644
--- a/src/swarm-topography/Swarm/Game/Scenario/Topography/Placement.hs
+++ b/src/swarm-topography/Swarm/Game/Scenario/Topography/Placement.hs
@@ -16,6 +16,7 @@ import Swarm.Game.Location
 import Swarm.Game.Scenario.Topography.Area
 import Swarm.Game.Scenario.Topography.Grid
 import Swarm.Language.Syntax.Direction (AbsoluteDir (..))
+import Swarm.Util (applyWhen)
 
 newtype StructureName = StructureName Text
   deriving (Eq, Ord, Show, Generic, FromJSON, ToJSON)
@@ -49,7 +50,7 @@ reorientLandmark (Orientation upDir shouldFlip) (AreaDimensions width height) =
   transposeLoc (Location x y) = Location (-y) (-x)
   flipV (Location x y) = Location x $ -(height - 1) - y
   flipH (Location x y) = Location (width - 1 - x) y
-  flipping = if shouldFlip then flipV else id
+  flipping = applyWhen shouldFlip flipV
   rotational = case upDir of
     DNorth -> id
     DSouth -> flipH . flipV
@@ -63,7 +64,7 @@ applyOrientationTransform (Orientation upDir shouldFlip) =
  where
   f = rotational . flipping
   flipV = NE.reverse
-  flipping = if shouldFlip then flipV else id
+  flipping = applyWhen shouldFlip flipV
   rotational = case upDir of
     DNorth -> id
     DSouth -> NE.transpose . flipV . NE.transpose . flipV
diff --git a/src/swarm-tui/Swarm/TUI/Controller.hs b/src/swarm-tui/Swarm/TUI/Controller.hs
index 3eb787ff8..665d00667 100644
--- a/src/swarm-tui/Swarm/TUI/Controller.hs
+++ b/src/swarm-tui/Swarm/TUI/Controller.hs
@@ -802,8 +802,8 @@ adjReplHistIndex d s =
   moveREPL :: REPLState -> REPLState
   moveREPL theRepl =
     newREPL
-      & (if replIndexIsAtInput (theRepl ^. replHistory) then saveLastEntry else id)
-      & (if oldEntry /= newEntry then showNewEntry else id)
+      & applyWhen (replIndexIsAtInput (theRepl ^. replHistory)) saveLastEntry
+      & applyWhen (oldEntry /= newEntry) showNewEntry
    where
     -- new AppState after moving the repl index
     newREPL :: REPLState
diff --git a/src/swarm-tui/Swarm/TUI/Editor/View.hs b/src/swarm-tui/Swarm/TUI/Editor/View.hs
index 057db5183..7e851ed18 100644
--- a/src/swarm-tui/Swarm/TUI/Editor/View.hs
+++ b/src/swarm-tui/Swarm/TUI/Editor/View.hs
@@ -25,6 +25,7 @@ import Swarm.TUI.Panel
 import Swarm.TUI.View.Attribute.Attr
 import Swarm.TUI.View.CellDisplay (renderDisplay)
 import Swarm.TUI.View.Util qualified as VU
+import Swarm.Util (applyWhen)
 
 extractTerrainMap :: UIState -> TerrainMap
 extractTerrainMap uis =
@@ -71,9 +72,8 @@ drawWorldEditor toplevelFocusRing uis =
     clickable n $ transformation w
    where
     transformation =
-      if Just n == maybeCurrentFocus
-        then withAttr BL.listSelectedFocusedAttr
-        else id
+      applyWhen (Just n == maybeCurrentFocus) $
+        withAttr BL.listSelectedFocusedAttr
 
   swatchContent list drawFunc =
     maybe emptyWidget drawFunc selectedThing
diff --git a/src/swarm-tui/Swarm/TUI/Launch/View.hs b/src/swarm-tui/Swarm/TUI/Launch/View.hs
index 7f4b532c0..91b917a3b 100644
--- a/src/swarm-tui/Swarm/TUI/Launch/View.hs
+++ b/src/swarm-tui/Swarm/TUI/Launch/View.hs
@@ -27,7 +27,7 @@ import Swarm.TUI.Launch.Prep
 import Swarm.TUI.Model.Name
 import Swarm.TUI.View.Attribute.Attr
 import Swarm.TUI.View.Util (EllipsisSide (Beginning), withEllipsis)
-import Swarm.Util (brackets, parens)
+import Swarm.Util (applyWhen, brackets, parens)
 
 drawFileBrowser :: FB.FileBrowser Name -> Widget Name
 drawFileBrowser b =
@@ -74,9 +74,7 @@ drawLaunchConfigPanel (LaunchOptions lc launchParams) =
   validatedOptions = toValidatedParams launchParams
   LaunchControls (FileBrowserControl fb _ isFbDisplayed) seedEditor ring displayedFor = lc
   addFileBrowser =
-    if isFbDisplayed
-      then (drawFileBrowser fb :)
-      else id
+    applyWhen isFbDisplayed (drawFileBrowser fb :)
 
   getFocusedConfigPanel :: Maybe ScenarioConfigPanelFocusable
   getFocusedConfigPanel = case focusGetCurrent ring of
@@ -86,9 +84,8 @@ drawLaunchConfigPanel (LaunchOptions lc launchParams) =
   isFocused = (== getFocusedConfigPanel) . Just
 
   highlightIfFocused x =
-    if isFocused x
-      then withDefAttr highlightAttr
-      else id
+    applyWhen (isFocused x) $
+      withDefAttr highlightAttr
 
   mkButton name label =
     clickable (ScenarioConfigControl $ ScenarioConfigPanelControl name)
diff --git a/src/swarm-tui/Swarm/TUI/Model/Dialog/Goal.hs b/src/swarm-tui/Swarm/TUI/Model/Dialog/Goal.hs
index c02ff33ea..e1acff4ff 100644
--- a/src/swarm-tui/Swarm/TUI/Model/Dialog/Goal.hs
+++ b/src/swarm-tui/Swarm/TUI/Model/Dialog/Goal.hs
@@ -23,6 +23,7 @@ import Servant.Docs qualified as SD
 import Swarm.Game.Scenario.Objective
 import Swarm.Game.Scenario.Objective.WinCheck
 import Swarm.TUI.Model.Name
+import Swarm.Util (applyWhen)
 
 -- | These are intended to be used as keys in a map
 -- of lists of goals.
@@ -118,8 +119,6 @@ constructGoalMap showHidden oc =
       filter (maybe False previewable . view objectivePrerequisite) inactiveGoals
 
   suppressHidden =
-    if showHidden
-      then id
-      else filter $ not . view objectiveHidden
+    applyWhen (not showHidden) $ filter $ not . view objectiveHidden
 
   (activeGoals, inactiveGoals) = partitionActiveObjectives oc
diff --git a/src/swarm-tui/Swarm/TUI/Model/Repl.hs b/src/swarm-tui/Swarm/TUI/Model/Repl.hs
index 1673194f0..f190829eb 100644
--- a/src/swarm-tui/Swarm/TUI/Model/Repl.hs
+++ b/src/swarm-tui/Swarm/TUI/Model/Repl.hs
@@ -73,6 +73,7 @@ import Servant.Docs qualified as SD
 import Swarm.Language.Syntax (SrcLoc (..))
 import Swarm.Language.Types
 import Swarm.TUI.Model.Name
+import Swarm.Util (applyWhen)
 import Swarm.Util.Lens (makeLensesNoSigs)
 import Prelude hiding (Applicative (..))
 
@@ -333,7 +334,7 @@ newREPLEditor t = applyEdit gotoEnd $ editorText REPLInput (Just 1) t
  where
   ls = T.lines t
   pos = (length ls - 1, T.length (last ls))
-  gotoEnd = if null ls then id else TZ.moveCursor pos
+  gotoEnd = applyWhen (not $ null ls) $ TZ.moveCursor pos
 
 initREPLState :: REPLHistory -> REPLState
 initREPLState hist =
diff --git a/src/swarm-tui/Swarm/TUI/Panel.hs b/src/swarm-tui/Swarm/TUI/Panel.hs
index c4b44e6e2..8361aeecd 100644
--- a/src/swarm-tui/Swarm/TUI/Panel.hs
+++ b/src/swarm-tui/Swarm/TUI/Panel.hs
@@ -18,6 +18,7 @@ import Brick.Focus
 import Brick.Widgets.Border
 import Control.Lens
 import Swarm.TUI.Border
+import Swarm.Util (applyWhen)
 
 data Panel n = Panel
   {_panelName :: n, _panelLabels :: BorderLabels n, _panelContent :: Widget n}
@@ -32,7 +33,7 @@ drawPanel attr fr = withFocusRing fr drawPanel'
  where
   drawPanel' :: Bool -> Panel n -> Widget n
   drawPanel' focused p =
-    (if focused then overrideAttr borderAttr attr else id) $
+    applyWhen focused (overrideAttr borderAttr attr) $
       borderWithLabels (p ^. panelLabels) (p ^. panelContent)
 
 -- | Create a panel.
diff --git a/src/swarm-tui/Swarm/TUI/View.hs b/src/swarm-tui/Swarm/TUI/View.hs
index bb6372dc3..64f2a179e 100644
--- a/src/swarm-tui/Swarm/TUI/View.hs
+++ b/src/swarm-tui/Swarm/TUI/View.hs
@@ -407,9 +407,8 @@ drawMainMenuEntry s = \case
   Quit -> txt "Quit"
  where
   highlightMessages =
-    if s ^. runtimeState . eventLog . notificationsCount > 0
-      then withAttr notifAttr
-      else id
+    applyWhen (s ^. runtimeState . eventLog . notificationsCount > 0) $
+      withAttr notifAttr
 
 drawAboutMenuUI :: Maybe Text -> Widget Name
 drawAboutMenuUI Nothing = centerLayer $ txt "About swarm!"
@@ -578,8 +577,8 @@ drawTPS s = hBox (tpsInfo : rateInfo)
     | s ^. uiState . uiGameplay . uiTiming . uiShowFPS =
         [ txt " ("
         , let tpf = s ^. uiState . uiGameplay . uiTiming . uiTPF
-           in (if tpf >= fromIntegral ticksPerFrameCap then withAttr redAttr else id)
-                (str (printf "%0.1f" tpf))
+           in applyWhen (tpf >= fromIntegral ticksPerFrameCap) (withAttr redAttr) $
+                str (printf "%0.1f" tpf)
         , txt " tpf, "
         , str (printf "%0.1f" (s ^. uiState . uiGameplay . uiTiming . uiFPS))
         , txt " fps)"
@@ -646,7 +645,13 @@ drawModal s = \case
 
 helpWidget :: Seed -> Maybe Port -> KeyEventHandlingState -> Widget Name
 helpWidget theSeed mport keyState =
-  padLeftRight 2 . vBox $ padTop (Pad 1) <$> [info, helpKeys, tips]
+  padLeftRight 2 . vBox $
+    padTop (Pad 1)
+      <$> [ info
+          , colorizationLegend
+          , helpKeys
+          , tips
+          ]
  where
   tips =
     vBox
@@ -660,6 +665,12 @@ helpWidget theSeed mport keyState =
       , txt ("Seed: " <> into @Text (show theSeed))
       , txt ("Web server port: " <> maybe "none" (into @Text . show) mport)
       ]
+  colorizationLegend =
+    vBox
+      [ heading boldAttr "Colorization legend"
+      , drawMarkdown
+          "In text, snippets of code like `3 + 4` or `scan down` will be colorized. Types like `Cmd Text`{=type} have a dedicated color. The names of an `entity`{=entity}, a `structure`{=structure}, and a `tag`{=tag} also each have their own color."
+      ]
   helpKeys =
     vBox
       [ heading boldAttr "Keybindings"
@@ -774,7 +785,7 @@ messagesWidget :: GameState -> [Widget Name]
 messagesWidget gs = widgetList
  where
   widgetList = focusNewest . map drawLogEntry' $ gs ^. messageNotifications . notificationsContent
-  focusNewest = if gs ^. temporal . paused then id else over _last visible
+  focusNewest = applyWhen (not $ gs ^. temporal . paused) $ over _last visible
   drawLogEntry' e =
     withAttr (colorLogs e) $
       hBox
@@ -1055,7 +1066,7 @@ drawItem sel i _ (Separator l) =
   -- element of the list, once it scrolls off the top of the viewport
   -- it will never become visible again.
   -- See https://github.com/jtdaugherty/brick/issues/336#issuecomment-921220025
-  (if sel == Just (i + 1) then visible else id) $ hBorderWithLabel (txt l)
+  applyWhen (sel == Just (i + 1)) visible $ hBorderWithLabel (txt l)
 drawItem _ _ _ (InventoryEntry n e) = drawLabelledEntityName e <+> showCount n
  where
   showCount = padLeft Max . str . show
@@ -1361,7 +1372,7 @@ drawRobotLog s =
   logEntriesToShow = getLogEntriesToShow s
   n = length logEntriesToShow
   drawEntry i e =
-    (if i == n - 1 && s ^. uiState . uiGameplay . uiScrollToEnd then visible else id) $
+    applyWhen (i == n - 1 && s ^. uiState . uiGameplay . uiScrollToEnd) visible $
       drawLogEntry (not allMe) e
 
   rid = s ^? gameState . to focusedRobot . _Just . robotID
diff --git a/src/swarm-tui/Swarm/TUI/View/CellDisplay.hs b/src/swarm-tui/Swarm/TUI/View/CellDisplay.hs
index 5b31df791..7f6a5f01c 100644
--- a/src/swarm-tui/Swarm/TUI/View/CellDisplay.hs
+++ b/src/swarm-tui/Swarm/TUI/View/CellDisplay.hs
@@ -161,7 +161,7 @@ displayEntityCell worldEditor ri coords =
       Coords xy = locToCoords $ P $ toHeading d
 
   displayForEntity :: EntityPaint -> Display
-  displayForEntity e = (if isKnownFunc ri e then id else hidden) $ getDisplay e
+  displayForEntity e = applyWhen (not $ isKnownFunc ri e) hidden $ getDisplay e
 
 -- | Get the 'Display' for a specific location, by combining the
 --   'Display's for the terrain, entity, and robots at the location, and
diff --git a/src/swarm-tui/Swarm/TUI/View/Robot.hs b/src/swarm-tui/Swarm/TUI/View/Robot.hs
index 18e30c5cc..1d90778d9 100644
--- a/src/swarm-tui/Swarm/TUI/View/Robot.hs
+++ b/src/swarm-tui/Swarm/TUI/View/Robot.hs
@@ -133,10 +133,7 @@ rowHdr :: RowHdr Name RobotWidgetRow
 rowHdr =
   RowHdr
     { draw = \_ (WdthD wd) (RowHdrCtxt (Sel s)) rh ->
-        let attrFn =
-              if s
-                then id
-                else withAttr rowHdrAttr
+        let attrFn = applyWhen (not s) $ withAttr rowHdrAttr
          in attrFn $ padRight (Pad $ if wd > 0 then 0 else 1) $ padLeft Max (str $ show rh)
     , width = \_ rh -> RowHdrW . (+ 2) . maximum0 $ map (length . show) rh
     , toRH = \_ (Ix i) -> i + 1
@@ -331,7 +328,7 @@ mkLibraryEntries c =
           ]
       nameTxt = r ^. robotName
 
-    highlightSystem = if r ^. systemRobot then withAttr highlightAttr else id
+    highlightSystem = applyWhen (r ^. systemRobot) $ withAttr highlightAttr
 
     ageStr
       | age < 60 = show age <> "sec"
diff --git a/src/swarm-tui/Swarm/TUI/View/Robot/Details.hs b/src/swarm-tui/Swarm/TUI/View/Robot/Details.hs
index 7ac6eb3be..40bcb17c2 100644
--- a/src/swarm-tui/Swarm/TUI/View/Robot/Details.hs
+++ b/src/swarm-tui/Swarm/TUI/View/Robot/Details.hs
@@ -22,6 +22,7 @@ import Swarm.Pretty (prettyText)
 import Swarm.TUI.Model.Name
 import Swarm.TUI.View.Attribute.Attr (boldAttr, cyanAttr)
 import Swarm.TUI.View.Robot.Type
+import Swarm.Util (applyWhen)
 
 renderRobotDetails :: FocusRing Name -> Robot -> RobotDetailsPaneState -> Widget Name
 renderRobotDetails ring r paneState =
@@ -42,7 +43,7 @@ renderRobotDetails ring r paneState =
     ]
  where
   highlightBorderFor n =
-    if isFocused then overrideAttr borderAttr cyanAttr else id
+    applyWhen isFocused $ overrideAttr borderAttr cyanAttr
    where
     isFocused = focusGetCurrent ring == Just (RobotsListDialog $ SingleRobotDetails n)
 
diff --git a/src/swarm-util/Data/BoolExpr/Simplify.hs b/src/swarm-util/Data/BoolExpr/Simplify.hs
index b36566ce8..ac0507e22 100644
--- a/src/swarm-util/Data/BoolExpr/Simplify.hs
+++ b/src/swarm-util/Data/BoolExpr/Simplify.hs
@@ -52,9 +52,8 @@ replace _ BFalse = BFalse
 replace m c@(BConst x) = case M.lookup varname m of
   Nothing -> c
   Just val ->
-    if txform val
+    if isPositive == val
       then BTrue
       else BFalse
  where
   (varname, isPositive) = extractConstFromSigned x
-  txform = if isPositive then id else not
diff --git a/test/integration/Main.hs b/test/integration/Main.hs
index 714e53eb9..f5ac0cbd0 100644
--- a/test/integration/Main.hs
+++ b/test/integration/Main.hs
@@ -80,7 +80,7 @@ import Swarm.TUI.Model (
 import Swarm.TUI.Model.DebugOption (DebugOption (LoadTestingScenarios))
 import Swarm.TUI.Model.StateUpdate (constructAppState, initPersistentState)
 import Swarm.TUI.Model.UI (UIState)
-import Swarm.Util (findAllWithExt)
+import Swarm.Util (applyWhen, findAllWithExt)
 import Swarm.Util.RingBuffer qualified as RB
 import Swarm.Util.Yaml (decodeFileEitherE)
 import System.FilePath (splitDirectories)
@@ -241,6 +241,7 @@ testScenarioSolutions rs ui key =
         , testSolution (Sec 10) "Challenges/gopher"
         , testSolution (Sec 5) "Challenges/hackman"
         , testSolution (Sec 5) "Challenges/blender"
+        , testSolution (Sec 10) "Challenges/dna"
         , testSolution (Sec 10) "Challenges/hanoi"
         , testSolution (Sec 3) "Challenges/lights-out"
         , testSolution (Sec 10) "Challenges/Sliding Puzzles/3x3"
@@ -578,7 +579,7 @@ testEditorFiles =
   testTextInFile :: Bool -> String -> Text -> FilePath -> TestTree
   testTextInFile whitespace name t fp = testCase name $ do
     let removeLW' = T.unlines . map (T.dropWhile isSpace) . T.lines
-        removeLW = if whitespace then removeLW' else id
+        removeLW = applyWhen whitespace removeLW'
     f <- T.readFile fp
     assertBool
       ( "EDITOR FILE IS NOT UP TO DATE!\n"
diff --git a/test/integration/TestRecipeCoverage.hs b/test/integration/TestRecipeCoverage.hs
index 4bf3dcce1..a99dd32e0 100644
--- a/test/integration/TestRecipeCoverage.hs
+++ b/test/integration/TestRecipeCoverage.hs
@@ -12,7 +12,7 @@ import Data.Set qualified as Set
 import Data.Text qualified as T
 import Swarm.Doc.Gen
 import Swarm.Game.Entity (Entity, EntityName, entityName)
-import Swarm.Util (quote)
+import Swarm.Util (applyWhen, quote)
 import Test.Tasty
 import Test.Tasty.ExpectedFailure (expectFailBecause)
 import Test.Tasty.HUnit
@@ -44,9 +44,8 @@ testRecipeCoverage = do
 expectNonCovered :: Entity -> TestTree -> TestTree
 expectNonCovered e =
   let name = T.toCaseFold (view entityName e)
-   in if name `elem` nonCoveredList
-        then expectFailBecause "More recipes needed (#1268)"
-        else id
+   in applyWhen (name `elem` nonCoveredList) $
+        expectFailBecause "More recipes needed (#1268)"
 
 -- | Known non-covered entities that need a recipe.
 nonCoveredList :: [EntityName]