.

wcfs/δbtail_test.go

@@ -1484,9 +1484,15 @@ func TestΔBTail(t *testing.T) {
 		"T1/T-T/B0:g-T2/B1:h-B2:g",
 		"T/T1/T-T2/B0:e-B1:f-B2:g",
 
-		// union: node is reachable from multiple parents
+		// ApplyΔ -> xunion: node is reachable from multiple parents
 		"T4/T1-T/T-T2-B4:c/T-T-T/B0:f-B1:h-B2:g,3:b",
 		"T1/T-T/T-T2/T-T-T/B0:f-B1:h-B2:f",
+		// ----//----
+		"T3/T1-T/T-T2-T/B0:b-T-T-B3:h/B1:e-B2:a",
+		"T1/T-T4/T-T2-T/T-T-T-T/B0:b-B1:e-B2:a,3:c-B4:e",
+		// ----//----
+		"T/T1,3/T-T2-T4/B0:b-T-T-B3:g-B4:c/B1:b-B2:e",
+		"T1,4/T-T-T/T-T2-B4:f/T-T-T/B0:h-B1:b-B2:h,3:a",
 
 		// XXX TODO classify
 		"T2/B1:a-B7:g", "T2,8/B1:a-B7:g-B9:i",