作者介紹 Philip Todd - Philip has a wealth of experience in a wide variety of mathematics including statistics, mathematical biology, constraint-based geometry systems and symbolic algebra algorithm development. He is the founder and president of Saltire Software, a company which specializes in software with high mathematical content incorporating their core technologies in constraint-based and symbolic geometry. Before founding Saltire, Phil was a Principal Software Engineer in the Computer Graphics department of the Tektronix Computer Research Labs in Beaverton, Oregon. Phil has degrees in mathematics from Cambridge University and Georgia Tech, and a Ph.D. from Dundee University. Eugene Fichter is a retired Professor of Mechanical Engineering from Oregon State university. His research interests include modelling insect locomotion and the design of walking machines. Dieter Mueller is currently studying Computer Engineering at George Fox University. He took interest in computers when he was young and has had an insatiable desire to learn more about them ever since. Dieter spent the summer compiling the Atlas of the Four-Bar Linkage and constructing clever mechanism designs from Geometry Expressions drawings for 3-D printing templates.