diff --git a/tests/test_new_functions.py b/tests/test_new_functions.py
new file mode 100644
index 0000000..f73a892
--- /dev/null
+++ b/tests/test_new_functions.py
@@ -0,0 +1,83 @@
+import torch
+import pytest
+from more_math.Parser.UnifiedMathVisitor import UnifiedMathVisitor
+from more_math.Parser.MathExprLexer import MathExprLexer
+from more_math.Parser.MathExprParser import MathExprParser
+from antlr4 import InputStream, CommonTokenStream
+
+def eval_math(expression, variables={}):
+    lexer = MathExprLexer(InputStream(expression))
+    stream = CommonTokenStream(lexer)
+    parser = MathExprParser(stream)
+    tree = parser.expr()
+    visitor = UnifiedMathVisitor(variables)
+    return visitor.visit(tree)
+
+def test_cossim():
+    a = torch.tensor([1.0, 0.0])
+    b = torch.tensor([1.0, 0.0])
+    # cossim([1,0], [1,0]) should be 1.0
+    res = eval_math("cossim(a, b)", {'a': a, 'b': b})
+    assert torch.isclose(res, torch.tensor(1.0))
+
+    c = torch.tensor([0.0, 1.0])
+    # cossim([1,0], [0,1]) should be 0.0
+    res2 = eval_math("cossim(a, c)", {'a': a, 'c': c})
+    assert torch.isclose(res2, torch.tensor(0.0), atol=1e-6)
+
+    # Test list support
+    res3 = eval_math("cossim([1,0], [0,1])")
+    assert torch.isclose(res3, torch.tensor(0.0), atol=1e-6)
+
+def test_flip():
+    a = torch.tensor([[1, 2], [3, 4]])
+    # flip(a, 0) -> [[3, 4], [1, 2]]
+    res = eval_math("flip(a, 0)", {'a': a})
+    expected = torch.tensor([[3, 4], [1, 2]])
+    assert torch.equal(res, expected)
+
+    # flip(a, 1) -> [[2, 1], [4, 3]]
+    res2 = eval_math("flip(a, 1)", {'a': a})
+    expected2 = torch.tensor([[2, 1], [4, 3]])
+    assert torch.equal(res2, expected2)
+
+    # Test list support for dims
+    # flip(a, [0, 1]) -> [[4, 3], [2, 1]]
+    res3 = eval_math("flip(a, [0, 1])", {'a': a})
+    expected3 = torch.tensor([[4, 3], [2, 1]])
+    assert torch.equal(res3, expected3)
+
+def test_cov():
+    # Covariance of identical vectors should be variance
+    a = torch.tensor([1.0, 2.0, 3.0])
+    res = eval_math("cov(a, a)", {'a': a})
+    expected = torch.var(a, correction=1).item()  # sample variance
+    assert abs(res - expected)<1e-6
+
+    # Covariance of roughly inverse
+    b = torch.tensor([3.0, 2.0, 1.0])
+    res2 = eval_math("cov(a, b)", {'a': a, 'b': b})
+    # Cov(a,b) for a=[1,2,3], b=[3,2,1]:
+    # means=2. sum((a-2)*(b-2)) = (-1*1 + 0*0 + 1*-1) = -2.
+    # div by N-1=2 -> -1.0
+    assert abs(res2 - -1.0)<1e-6
+
+    # Test list
+    res3 = eval_math("cov([1,2,3], [3,2,1])")
+    assert abs(res3 - -1.0)<1e-6
+
+    # Test mismatch error
+    with pytest.raises(ValueError, match="same number of elements"):
+        eval_math("cov([1,2], [1,2,3])")
+
+
+def test_sort():
+    a = torch.tensor([3.0, 1.0, 2.0])
+    res = eval_math("sort(a)", {'a': a})
+    expected = torch.tensor([1.0, 2.0, 3.0])
+    assert torch.equal(res, expected)
+
+    # Test list support
+    res2 = eval_math("sort([3, 1, 2])")
+    # Output of sort on list promoted to tensor is tensor
+    assert torch.equal(res2, torch.tensor([1.0, 2.0, 3.0], device=res2.device))