public void testVariableEqualsConstant()
{
Variable var1 = new Variable("x");
Constant constant = new Constant("John");
Dictionary<Variable, Term> result = unifier.unify(var1, constant, theta);
Assert.AreEqual(theta, result);
Assert.AreEqual(1, theta.Keys.Count);
Assert.IsTrue(theta.ContainsKey(var1));
Assert.AreEqual(constant, theta[var1]);
}