"Is the difference between "*whether or not*" an..."


by Sylvain Chevalier Aug 22 2016

Is the difference between "whether or not" and "if" trivial in english (I'm French) ? I think I understand the third point in the Caveats section. However I only understand the last sentence from context. Is there already an explanation on Arbital of the difference between "whether or not" and "if" as used here ?


Patrick Stevens

This is not universally agreed-upon, but I use "$~$A$~$ decides whether or not $~$B$~$ holds" to mean "$~$A$~$ outputs $~$1$~$ if $~$B$~$ holds, and outputs $~$0$~$ otherwise".

If I said "$~$A$~$ decides if $~$B$~$ holds", I would consider that ambiguous: it might mean "$~$A$~$ outputs $~$1$~$ if $~$B$~$ holds" without the requirement on $~$A$~$'s behaviour if $~$B$~$ doesn't hold.