We will here describe the practical consequences of the theoretical results mentioned on the previous page
During the evaluation of an expression, it will never be necessary to backtrack the evaluation process
in order to reach a normal form.
An expression cannot be converted to two different normal forms (modulo alpha conversions, of course).
If an expression e somehow can be reduced to f in one or more steps, f can be reached by
normal order reduction - but not necessarily by applicative order reduction
Normal-order reduction is more powerful than the applicative-order reduction
Scheme and ML uses applicative-order reduction
Haskell is an example of a functional programming language with normal-order reduction