diff -r c71a7d863c2e -r b8d72909d593 tests/mirrored-studs.py
--- a/tests/mirrored-studs.py	Mon Jun 24 11:48:52 2019 +0300
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,25 +0,0 @@
-from testsuite import problem_type, report_problem
-import linetypes
-from librarystandards import library_standards
-
-@problem_type('mirrored-studs',
-    severity = 'warning',
-    message = lambda primitive: str.format(
-        '"{primitive}" should not be mirrored',
-        primitive = primitive,
-    )
-)
-def mirrored_studs_test(model):
-    for subfile_reference in model.subfile_references:
-        # Test whether any stud subfile is mirrored.
-        # A subfile is mirrored if its determinant is negative.
-        if subfile_reference.subfile_path.startswith('stu') \
-        and subfile_reference.subfile_path != 'stud4.dat' \
-        and subfile_reference.matrix.determinant() < 0:
-            yield report_problem(
-                'mirrored-studs',
-                bad_object = subfile_reference,
-                primitive = subfile_reference.subfile_path,
-            )
-
-manifest = {'tests': [mirrored_studs_test]}