gives the total number of indivisible subexpressions in expr.
- LeafCount gives a measure of the total "size" of an expression.
- LeafCount counts the number of subexpressions in expr that correspond to "leaves" on the expression tree.
- LeafCount is based on FullForm representation of expressions.
- Numbers with heads Rational and Complex are treated as composite objects, just as in FullForm.
Introduced in 1988