diff --git a/mathics/builtin/testing_expressions/equality_inequality.py b/mathics/builtin/testing_expressions/equality_inequality.py
index bf339dcc7..9b193f7f1 100644
--- a/mathics/builtin/testing_expressions/equality_inequality.py
+++ b/mathics/builtin/testing_expressions/equality_inequality.py
@@ -253,7 +253,6 @@ def eval_other(self, args, evaluation):
 
 
 class _MinMax(Builtin):
-
     attributes = (
         A_FLAT | A_NUMERIC_FUNCTION | A_ONE_IDENTITY | A_ORDERLESS | A_PROTECTED
     )
diff --git a/mathics/builtin/testing_expressions/list_oriented.py b/mathics/builtin/testing_expressions/list_oriented.py
index b2f819331..30c0668a3 100644
--- a/mathics/builtin/testing_expressions/list_oriented.py
+++ b/mathics/builtin/testing_expressions/list_oriented.py
@@ -39,6 +39,14 @@ class ArrayQ(Builtin):
      = False
     >> ArrayQ[{{a, b}, {c, d}}, 2, SymbolQ]
      = True
+
+    ArrayQ works on sparse arrays:
+    >> ArrayQ[SparseArray[{{1, 2} -> a, {2, 1} -> b}]]
+     = True
+
+    For sparse arrays, ArrayQ tests not only specified values, but also default value 0:
+    >> ArrayQ[SparseArray[{{1, 2} -> a, {2, 1} -> b}], 2, SymbolQ]
+     = False
     """
 
     rules = {