TRANSFERRING CONSTRAINT DESCRIPTORS BETWEEN LIGHT-WEIGHT DEVICES FOR DOCUMENT ACCESS

Information about documents is transferred between machines in the form of constraint descriptors. A first machine can obtain a constraint descriptor that includes information about a set of constraints that documents can satisfy. The first machine can transfer the constraint descriptor to a second machine that is capable of using the constraint descriptor to access documents that satisfy the set of constraints. Similarly, the second machine can receive a data packet from the first machine, where the data packet includes an encoding of the constraint descriptor. The second machine can decode the data packet to obtain the constraint descriptor. Each of the machines can be a portable computing device or a fixed computing device. The first machine can receive user signals through its user interface, defining an attribute-value relation, and the first machine can compile a constraint using the user signals. Or the first machine can receive user signals selecting a stored constraint descriptor. In response to user signals, is the second machine can solve the set of constraints and can use the solution to obtain document references, such as Web URLs, indicating documents that satisfy the set of constraints. The user can then request more detail, or can obtain a printed version of a document.