src/sage/groups/matrix_gps/coxeter_group.py: Do not use sage.symbolic for easy cases of cos(pi/x) (fixup)

Matthias Koeppe · Matthias Koeppe · commit 2511e3e18995 · 2022-02-27T16:45:24.000-08:00
diff --git a/src/sage/groups/matrix_gps/coxeter_group.py b/src/sage/groups/matrix_gps/coxeter_group.py
@@ -292,6 +292,8 @@ def val(x):
             def val(x):
                 if x == -1:
                     return 2
+                elif x == 1:
+                    return -2
                 elif x == 2:
                     return 0
                 elif x == 3:
