We investigate the class PBD of π-Calculus processes that are bounded in the function depth. First, we show that boundedness in depth has an intuitive characterisation when we understand processes as graphs: a process is bounded in depth if and only if the length of the simple paths is bounded. The proof is based on a new normal form for the π-Calculus called anchored fragments. Using this conc...

Machine learning research has been very successful at producing powerful, broadlyapplicable classification learners. However, many practical learning problems do not fit the classification framework well, and as a result the initial phase of suitably formulating the problem and incorporating the relevant domain knowledge can be very difficult and typically consumes the majority of the project t...

In this paper, we propose a new mechanism, imitation, which can be used in a programming by demonstration system as an alternative to generalization. A system using imitation always asks the user for help when a new case arises in an algorithm. At this point, the user may demonstrate the steps for this case or tell the system: (1) that this case is similar to another one already demonstrated an...

A pairwise balanced design, B(K; v), is a block design on v points, with block sizes taken from K, and with every pair of points occurring in a unique block; for a fixed K, B(K) is the set of all v for which a B(K; v) exists. A set, S, is a PBD-basis for the set, T , if T = B(S). Let Na(m) = {n : n ≡ a mod m}, and N≥m = {n : n ≥ m}; with Q the corresponding restriction of N to prime powers. Thi...

A Latin square of order s is an s by s array L of the symbols { 1,2,..., s}, such that each symbol occurs once in each row and column of L. Two Latin squares L and M of order s are orthogonal if their superposition yields all s2 possible ordered pairs (i,j), 1 < i, j < s. It was conjectured by Euler, and proved by Tarry [4] that there do not exist a pair of orthogonal Latin squares of order six...

In a programming by demonstration system, examples provided by the user are generalized to form abstractions that are used by the system. There are several reasons why the system and the user should collaborate to annotate examples with knowledge that guides generalization. These include dealing with inconsistencies among examples or the underlying domain theory, making queries in order to spee...

Research in learning from demonstration has focused on transferring movements from humans to robots. However, a need is arising for robots that do not just replicate the task on their own, but that also interact with humans in a safe and natural way to accomplish tasks cooperatively. Robots with variable impedance capabilities opens the door to new challenging applications, where the learning a...

Having the computer imitate recorded human actions is the basis for an experimental technology for programming, variously called "Programming by Example" or "Programming by Demonstration". This is an under-appreciated technology that holds the promise of revolutionizing programming and making it more accessible, especially to non-expert programmers. Because imitation is a natural learning strat...