0 a fraction in which either the numerator (= the number above the line) or the denominator (= the number below the line) is itself a fraction --
1 a fraction (= division of a number) in which either the numerator (= number above the line) or the denominator (= number below the line) is itself a fraction --
As another example, one might consider the complex fractions.
Numerators and denominators are also used in fractions that are not "common", including compound fractions, complex fractions, and mixed numerals.
If, in a complex fraction, there is no clear way to tell which fraction lines takes precedence, then the expression is improperly formed, and ambiguous.
A "complex fraction" is a fraction whose numerator or denominator, or both, contains a fraction.
To reduce a complex fraction to a simple fraction, treat the longest fraction line as representing division.
When she jumped up from her easy-chair, she was trying to reduce the following complex fractions, into one simple one, and entirely failed.
