adding a test

Author: mmatera

test/builtin/numbers/test_linalg.py

@@ -211,6 +211,12 @@ def test_inverse(str_expr, str_expected, fail_msg, warnings):
             "SingularValueDecomposition[{1, {2}}]",
             None,
         ),
+        (
+            "A = Array[a, {2,2}]; Eigenvalues[A.ConjugateTranspose[A]] // FullSimplify",
+            None,
+            "{-Sqrt[(a[1, 1] Conjugate[a[1, 1]] + a[1, 2] Conjugate[a[1, 2]] + a[2, 1] Conjugate[a[2, 1]] + a[2, 2] Conjugate[a[2, 2]]) ^ 2 - 4 a[1, 1] a[2, 2] Conjugate[a[1, 1]] Conjugate[a[2, 2]] - 4 a[1, 2] a[2, 1] Conjugate[a[1, 2]] Conjugate[a[2, 1]] + 4 a[1, 1] a[2, 2] Conjugate[a[1, 2]] Conjugate[a[2, 1]] + 4 a[1, 2] a[2, 1] Conjugate[a[1, 1]] Conjugate[a[2, 2]]] / 2 + a[1, 1] Conjugate[a[1, 1]] / 2 + a[1, 2] Conjugate[a[1, 2]] / 2 + a[2, 1] Conjugate[a[2, 1]] / 2 + a[2, 2] Conjugate[a[2, 2]] / 2, Sqrt[(a[1, 1] Conjugate[a[1, 1]] + a[1, 2] Conjugate[a[1, 2]] + a[2, 1] Conjugate[a[2, 1]] + a[2, 2] Conjugate[a[2, 2]]) ^ 2 - 4 a[1, 1] a[2, 2] Conjugate[a[1, 1]] Conjugate[a[2, 2]] - 4 a[1, 2] a[2, 1] Conjugate[a[1, 2]] Conjugate[a[2, 1]] + 4 a[1, 1] a[2, 2] Conjugate[a[1, 2]] Conjugate[a[2, 1]] + 4 a[1, 2] a[2, 1] Conjugate[a[1, 1]] Conjugate[a[2, 2]]] / 2 + a[1, 1] Conjugate[a[1, 1]] / 2 + a[1, 2] Conjugate[a[1, 2]] / 2 + a[2, 1] Conjugate[a[2, 1]] / 2 + a[2, 2] Conjugate[a[2, 2]] / 2}",
+            "Sympy issue #1156",
+        ),
     ],
 )
 def test_private_doctests_linalg(str_expr, msgs, str_expected, fail_msg):