small changes

Author: Jonathan Kliem

src/sage/geometry/polyhedron/base.py

@@ -4423,6 +4423,13 @@ def stack(self, face, position=None):
              A ray in the direction (1, 1),
              A vertex at (2, 0))
 
+        Stacking requires a proper face::
+
+            sage: Q.stack(Q.faces(2)[0])
+            Traceback (most recent call last):
+            ...
+            ValueError: can only stack on proper face
+
         TESTS:
 
         Checking that the backend is preserved::
@@ -4432,8 +4439,9 @@ def stack(self, face, position=None):
             sage: stack.backend()
             'field'
 
-        Checking that stacked point needs to be in the interior of
-        ``locus_polyhedron``::
+        The stacked vertex may not satisfy any inequality
+        defining the original polyhedron::
+
             sage: P = polytopes.octahedron()
             sage: P.stack(P.faces(2)[0],4)
             Traceback (most recent call last):

src/sage/geometry/polyhedron/representation.py

@@ -447,7 +447,7 @@ def b(self):
 
     def neighbors(self):
         """
-        Iterate over the adjacent facets (i.e. inequalities/equations)
+        Iterate over the adjacent facets (i.e. inequalities).
 
         Only defined for inequalities.
 
@@ -464,7 +464,7 @@ def neighbors(self):
 
         TESTS:
 
-        Checking that it works for polyhedra with equations::
+        Checking that :trac:`28463` is fixed::
 
         sage: P = polytopes.simplex()
         sage: F1 = P.Hrepresentation()[1]
@@ -473,17 +473,18 @@ def neighbors(self):
          An inequality (0, 0, 1, 0) x + 0 >= 0,
          An inequality (0, 0, 0, 1) x + 0 >= 0]
 
-        Does not work for inequalities::
+        Does not work for equalities::
 
         sage: F0 = P.Hrepresentation()[0]
         sage: list(F0.neighbors())
         Traceback (most recent call last):
         ...
-        AssertionError: must be inequality
+        TypeError: must be inequality
         """
         # The adjacency matrix does not include equations.
         n_eqs = self.polyhedron().n_equations()
-        assert self.is_inequality(), "must be inequality"
+        if not self.is_inequality():
+            raise TypeError("must be inequality")
 
         adjacency_matrix = self.polyhedron().facet_adjacency_matrix()
         for x in self.polyhedron().Hrep_generator():