Christos Papadimitriou David Parnas - information hiding, modular programming Yale Patt - ILP[disambiguation needed], speculative architectures David A. Patterson Judea Pearl - artificial intelligence, Search[disambiguation needed] Alan Perlis - Programming Pearls Radia Perlman - spanning tree protocol Simon Peyton Jones - functional programming Gordon Plotkin Amir Pnueli - temporal logic Willem van der Poel - computer graphics, robotics, geographic information systems, imaging, multimedia, virtual environments, games Martha Pollack - intentions in planning Emil Post - mathematics Jon Postel - Internet Franco Preparata