We present two purely functional implementations of the computational diierentiation tools { the well known numeric (not symbolic!) techniques which permit to compute point-wise derivatives of functions deened by computer programs economically and exactly. We show how the co-recursive (lazy) algorithm formulation permits to construct in a transparent and elegant manner the entire innnite tower ...

This paper describes a software package, which allows students compiling programs using web-based interface and Internet connections. Several different computer languages such as C, C++, Fortran, Pascal, and JAVA are implemented. In case of some languages several different compilers can be used and different error messages received. This helps students to track their errors. The access to compi...

Interim Reports on work of the International Institute for Applied Systems Analysis receive only limited review. Views or opinions expressed herein do not necessarily represent those of the Institute, its National Member Organizations, or other organizations supporting the work. Abstract Modeling earthquakes plays an important role in investigation of different aspects of seismic risk. The pape...

Computer programs are increasingly being called on to suggest or to make decisions in medical applications. Traditional methods of decision making based on flowcharts and probabilistic classification have proven to be too cumbersome to apply to large domains. As a result, programs employing artificial intelligence methods were introduced in the 1970’s. Deficiencies in those methods limited the ...

We explore the question of what properties of LISP programs can be made \obvious" to a computer system. We present a polynomial-time algorithm for inferring interesting properties of pure LISP programs. Building on previous work in knowledge representation for rapid inference, we present a language for representing properties of programs. We treat properties as generalized types, i.e., sets of ...

Would it be possible to explain the emergence of new computational ideas using the computation itself? Would it be feasible to describe the discovery process of new algorithmic solutions using only mathematics? This study is the first effort to analyze the nature of such inquiry from the viewpoint of effort to find a new algorithmic solution to a given problem. We define program reachability as...

Ermr flow analysis is the study of how errors originate, spread, and propagate during progmm execution based on the three steps of the fault/failure model: execution, infection, and propagation[l6]. These three steps are defined relative to a virtual computer by judiciously selecting the instruction set and data state of this computer the need for infection analysis can be reduced or eliminated...

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Programs developed with standard techniques often fail when they encounter any of a variety of internal errors. We present a set of techniques that prevent programs from failing and instead enable them to continue to execute even after they encounter otherwise fatal internal errors. Our results indicate that even though the techniques may take the program outside of its anticipated execution en...