Well-Defined
An expression is called well-defined (or Unambiguous) if its definition assigns it a unique interpretation orvalue. Otherwise, the expression is said to not be well defined or to be Ambiguous.
For example, the expression 
(the Product) is well-defined if 
, 
, and 
are integers. Because integersare Associative, has the same value whether it is interpreted to mean 
or 
. However, if , ,and are Cayley Numbers, then the expression is not well-defined, sinceCayley Number are not, in general, Associative, so that the two interpretations and can be different.
Sometimes, ambiguities are implicitly resolved by notational convention. For example, the conventional interpretation of
is 
, never 
, so that the expression 
is well-defined eventhough exponentiation is nonassociative.
- Ahlfors-Bers Theorem
- A-Integrable
- Airy Differential Equation
- Airy-Fock Functions
- Airy Functions
- Airy Projection
- Aitken Interpolation
- Aitken's Delta Squared Process
- Ajima-Malfatti Points
- Albanese Variety
- Albers Conic Projection
- Albers Equal-Area Conic Projection
- Alcuin's Sequence
- Aleksandrov-Cech Cohomology
- Aleksandrov's Uniqueness Theorem
- Aleph
- Aleph-0
- Aleph-1
- Alethic
- Alexander-Conway Polynomial
- Alexander Ideal
- Alexander Invariant
- Alexander Matrix
- Alexander Polynomial
- Alexander's Horned Sphere