diff --git a/testcases/automatic/usage-check-1.occ.test b/testcases/automatic/usage-check-1.occ.test
index e558c2b..fc0197e 100644
--- a/testcases/automatic/usage-check-1.occ.test
+++ b/testcases/automatic/usage-check-1.occ.test
@@ -22,10 +22,20 @@ PROC m()
     a[0] := 3
     a[0] := 4
 
+%FAIL Identical constants, PAR assign
+    a[0],a[0] := 3,4
+
 %PASS Same constant, different array
     a[0] := 3
     b[0] := 4
 
+%FAIL Identical variables
+    x := 3
+    x := 4
+
+%FAIL Identical variables, PAR assign
+    x,x := 3,4
+
 %FAIL Variable and a constant
     a[0] := 3
     a[x] := 4
diff --git a/testcases/automatic/usage-check-3.occ.test b/testcases/automatic/usage-check-3.occ.test
new file mode 100644
index 0000000..7804881
--- /dev/null
+++ b/testcases/automatic/usage-check-3.occ.test
@@ -0,0 +1,33 @@
+-- This file tests simple array uses without replication
+-- Four unknown variables are available; x, y, z.
+-- Two arrays are automatically declared; a (size 10) and b (size 12)
+
+PROC p(INT x, y, z)
+  [10]INT a:
+  [12]INT b:
+%%
+:
+
+PROC m()
+  SKIP
+:
+
+%FAIL same items in SEQ replicator
+  SEQ i = 0 FOR 6
+    PAR
+      a[i] := 3
+      a[i] := 4
+
+%FAIL Modulo items in SEQ replicator (unsafe)
+  SEQ i = 0 FOR 6
+    PAR
+      a[(i + 1) REM 4] := 3
+      a[i] := 4
+
+%PASS Modulo items in SEQ replicator (safe)
+  SEQ i = 0 FOR 6
+    PAR
+      a[(i + 1) REM 5] := 3
+      a[i] := 4
+
+%
diff --git a/transformations/ArrayUsageCheckTest.hs b/transformations/ArrayUsageCheckTest.hs
index 89130c9..2978264 100644
--- a/transformations/ArrayUsageCheckTest.hs
+++ b/transformations/ArrayUsageCheckTest.hs
@@ -767,6 +767,7 @@ ioqcTests :: IO (Test, [QuickCheckTest])
 ioqcTests
   = do usageCheckTest1 <- automaticTest "testcases/automatic/usage-check-1.occ.test"
        usageCheckTest2 <- automaticTest "testcases/automatic/usage-check-2.occ.test"
+       usageCheckTest3 <- automaticTest "testcases/automatic/usage-check-3.occ.test"
        return
         (TestList
         [
@@ -775,6 +776,7 @@ ioqcTests
          ,testMakeEquations
          ,usageCheckTest1
          ,usageCheckTest2
+         ,usageCheckTest3
         ]
         ,qcOmegaEquality ++ qcOmegaPrune)