ZeroExpression -- the class of all zero expressions
The type ZeroExpression is a member of the class Type.
Each object of class ZeroExpression is called a zero expression.
Each zero expression is also a member of class Holder.
More general types (whose methods may also apply) :
ZeroExpression -- a type of Expression of which
there is just one instance, an expression representing the number 0.
Methods for using a zero expression :