.. method:: __eq__(expr)
Test whether two linear expressions are equal.
+ Unlike methods :meth:`LinExpr.__lt__`, :meth:`LinExpr.__le__`, :meth:`LinExpr.__ge__`, :meth:`LinExpr.__gt__`, the result is a boolean value, not a polyhedron.
+ To express that two linear expressions are equal or not equal, use functions :func:`Eq` and :func:`Ne` instead.
As explained below, it is possible to create polyhedra from linear expressions using comparison methods.
A *convex polyhedron* (or simply "polyhedron") is the space defined by a system of linear equalities and inequalities.
This space can be unbounded.
+A *Z-polyhedron* (simply called "polyhedron" in LinPy) is the set of integer points in a convex polyhedron.
.. class:: Polyhedron(equalities, inequalities)
Polyhedron(string)