Sum -- the class of all sum expressions

Functions and methods returning a sum expression :

• Expression - Expression -- see Expression -- the class of all expressions

Methods that use a sum expression :

• Expression + Sum (missing documentation)
• RingMap Sum (missing documentation)
• substitute(Sum,Thing) -- see substitute -- substituting values for variables
• Sum + Expression (missing documentation)
• Sum + ZeroExpression (missing documentation)
• ZeroExpression + Sum (missing documentation)

For the programmer

The object Sum is a wrapper type, with ancestor classes AssociativeExpression < Expression < BasicList < Thing.