Re: Peculiar output from Union ?
- To: mathgroup at smc.vnet.net
- Subject: [mg108522] Re: Peculiar output from Union ?
- From: "Carl K. Woll" <carlw at wolfram.com>
- Date: Sun, 21 Mar 2010 02:07:43 -0500 (EST)
On 3/20/2010 3:46 AM, Jack L Goldberg 1 wrote: > Hi Folks, > > Can anyone explain this: > > In[1]:= Union[ 1< x< 2, 3< x< 5 ] > > Out[1]= 5< x > > ?? > > The FullForm is: Union[ Less[1, x, 2], Less[3, x, 5] ] which evaluates to: Less[1, 2, 3, 5, x] because that's the way Union works for any head. Usually the head is List, not Less. From the help: The Subscript[list, i] must have the same head, but it need not be List. The above Less expression evaluates to Less[5, x] Carl Woll Wolfram Research > I am using a MacBook Pro, OS 10.6.2 > > Thanks, > > Jack > >