Difference between revisions of "Beta reduction"
From HaskellWiki
BrettGiles (talk  contribs) (2 cents on wording / links.) 
(I think my example actually included an etareduction as well as a beta conversion. Edited example.) 

Line 3:  Line 3:  
For example, suppose we have 
For example, suppose we have 

<haskell> 
<haskell> 

−  +  2*x*x + y 

</haskell> 
</haskell> 

If we now replace every occurance of <hask>x</hask> with 7, we arrive at 
If we now replace every occurance of <hask>x</hask> with 7, we arrive at 

<haskell> 
<haskell> 

−  +  2*7*7 + y 

</haskell> 
</haskell> 

We have thus performed a ''beta reduction''. 
We have thus performed a ''beta reduction''. 

−  
⚫  
Also see [[Lambda calculus]] and the [http://en.wikipedia.org/wiki/Lambda_calculus wikipedia lambda calculus article]. 
Also see [[Lambda calculus]] and the [http://en.wikipedia.org/wiki/Lambda_calculus wikipedia lambda calculus article]. 

+  
⚫ 
Revision as of 12:55, 30 January 2007
A beta reduction (also written β reduction) is where you actually apply a lambda function to an expression to generate a result.
For example, suppose we have
2*x*x + y
If we now replace every occurance of x
with 7, we arrive at
2*7*7 + y
We have thus performed a beta reduction.
Also see Lambda calculus and the wikipedia lambda calculus article.