# Avoid trial and error with Wolfram|Alpha?

GROUPS:
 Often I try to test some Wolfram Language (WL) expression within Wolfram|Alpha (Just the standard Web-Interface or WinPhone App). Its hopeless concerning use of WL and structuring expressions. Some few WL-expressions are understood. Most of them are not understood. Always it ends up in an endless trial and error process, since WA does not understand what I mean.Unfortunately there is no Wolfram|Alpha documentation since it claims to be self-explaining. But it is very far from that. Is there some link where I can at least learn how to use WL within Wolfram|Alpha? I can enter Subsets[{1,2,3,4,5},{3}] I can enter as well Union[{{1,2,3},{2,3,4}},{{3,4,5}}] But I cannot enter Union[Subsets[{1,2,3,4,5},{3}],{{3,4,5}}] This is misunderstood.Of course I tried the same with natural language input. Something like (subsets of {1,2,3,4,5} with size 3) union {{3,4,5}} This doesn't work either.