common-lisp:standard-object, sb-pcl::slot-object, common-lisp:t

load-bearing-block, movable-block

The superclass of all objects in the Blocks World (not including the hand).

Subclasses of basic-block characterize different kinds of objects, and have different properties.

They all have a name, given as block-name and in the examples from the book, a global variable of that name is used to refer to them.

Since this chapter is an explanation of CLOS, no specific constructor function is defined, and users may call make-instance directly.