1. At a computing device in a distributed system, a method of converting a set form of a policy expression into a Boolean form of the policy expression to assist a communications endpoint in complying with the policy expression, the method comprising acts of: accessing a set form of a policy expression, the set form of the policy expression defined by a plurality of policy assertions arbitrarily constrained by a first group of logical operators, the first group of logical operators configured for defining policy expressions in set form, the set form of the policy expression convertible to any of plurality of other forms of the policy expression, including other forms of the policy expression defined by a plurality of equivalent arbitrary constrained policy assertions, at least one of the other forms being the Boolean form of the policy expression, the Boolean form of the policy expression defined by the plurality of policy assertions arbitrarily constrained by a second different group of logical operators, the second different group of logical operators configured for defining policy expressions in Boolean form, the Boolean form of the policy expression convertible to the set form and any of the plurality of other forms, one or more lines of the Boolean form of the policy expression beginning with a logical operator selected from the second group of logical operators; utilizing a policy algebra to convert the set form of the policy expression to the Boolean form of the policy expression by converting the plurality of policy assertions constrained by the first group of logical operators to an equivalent plurality of policy assertions constrained by the second group of logical operators, the equivalent plurality of policy assertions representing policy alternatives corresponding to each possible combination of one or more of the plurality of policy assertions that will satisfy the policy expression; and presenting the equivalent plurality of policy assertions to the communications endpoint such that the communications endpoint can identify one of the plurality of policy alternatives from the Boolean form of the policy expression for use in complying with the policy expression.