Normal[expr] converts expr to a normal expression, from a variety of special forms.
Normal[expr] converts a power series to a normal expression by truncating higher-order terms.
Normal[expr] converts SparseArray objects into ordinary arrays.
Normal[expr] converts RootSum objects into explicit sums involving Root objects.
When additional "data types" are introduced, Normal should be defined to convert them, when possible, to normal expressions.
See Section 1.5.10, Section 2.4.5, Section 3.4.3 and Section 3.6.5.
See also: SeriesCoefficient.
New in Version 1.0; modified in 5.0.