contract Owned is DBC {

    // FIELDS

    address public owner;

    // NON-CONSTANT METHODS

    function Owned() { owner = msg.sender; }

    function changeOwner(address ofNewOwner) pre_cond(isOwner()) { owner = ofNewOwner; }

    // PRE, POST, INVARIANT CONDITIONS

    function isOwner() internal returns (bool) { return msg.sender == owner; }

}
function isOwner() internal returns (bool) { return msg.sender == owner; }

// PRE, POST, INVARIANT CONDITIONS