diff --git a/checker.go b/checker.go
index 01c9566..5668760 100644
--- a/checker.go
+++ b/checker.go
@@ -26,6 +26,11 @@ type linearizationInfo struct {
 	partialLinearizations [][][]int // for each partition, a set of histories (list of ids)
 }
 
+func (info *linearizationInfo) AddOperations(operations []Operation) {
+	info.partialLinearizations = append(info.partialLinearizations, [][]int{})
+	info.history = append(info.history, makeEntries(operations))
+}
+
 type byTime []entry
 
 func (a byTime) Len() int {
diff --git a/visualization/index.js b/visualization/index.js
index 6988c4d..33aa938 100644
--- a/visualization/index.js
+++ b/visualization/index.js
@@ -329,6 +329,10 @@ function render(data) {
       const width = xPos[el['End']] - rx
       const x = rx + XOFF + PADDING
       const y = PADDING + el['ClientId'] * (BOX_HEIGHT + BOX_SPACE)
+      let rectClass = 'linearization-rect';
+      if (partition['PartialLinearizations'].length === 0) {
+        rectClass = 'non-linearization-rect'
+      }
       rects.push(
         svgadd(g, 'rect', {
           height: BOX_HEIGHT,
@@ -337,7 +341,7 @@ function render(data) {
           y: y,
           rx: HISTORY_RECT_RADIUS,
           ry: HISTORY_RECT_RADIUS,
-          class: 'history-rect',
+          class: rectClass,
         })
       )
       const text = svgadd(g, 'text', {