Joins and Intersections

Dedicated to the memory of Wolfgang Classical Intersection Theory (see for example Wei! [Wei]) treats the case of proper intersections, where geometrical objects (usually subvarieties of a non­ singular variety) intersect with the expected dimension. In 1984, two books appeared which surveyed and developed work by the individual authors, co­ workers and others on a refined version of Intersection Theory, treating the case of possibly improper intersections, where the intersection could have ex­