eta conversion

1 definition found

eta conversion - Free On-line Dictionary of Computing (26 May 2007) :

  eta conversion
  eta abstraction
  eta expansion
  eta reduction
  
     <theory> In lambda-calculus, the eta conversion rule states
  
     	\ x . f x  <-->  f
  
     provided x does not occur as a free variable in f and f is a
     function.  Left to right is eta reduction, right to left is
     eta abstraction (or eta expansion).
  
     This conversion is only valid if bottom and \ x . bottom are
     equivalent in all contexts.  They are certainly equivalent
     when applied to some argument - they both fail to terminate.
     If we are allowed to force the evaluation of an expression in
     any other way, e.g. using seq in Miranda or returning a
     function as the overall result of a program, then bottom and
     \ x . bottom will not be equivalent.
  
     See also observational equivalence, reduction.