If you use the align
environment without any &
characters, it right-aligns your equations. Who ever right-aligns equations?
If you use an align
or align*
environment and don't provide one or more &
markers for each and every row, you're probably misusing the environment. (If you want to center the rows, use a gather
or gather*
environment.) Don't expect the software to bail you out and somehow intuit -- correctly, no less... -- where the alignment points are supposed to go.
Right-aligning the rows that are lacking &
characters, then, is align
's way of delivering a powerful and difficult-to-ignore visual message -- the equivalent of "Uh oh, I think you've messed up." Much more powerful, for sure, than issuing a warning message -- which many (most?) users tend to ignore anyway, right? Of course, if for some reason a user does want to right-align the row(s), then that's what he/she gets -- without being bombarded with patronizing warning messages.
The upshot: If you do not provide &
alignment markers in each and every row of an align
or align*
environment, you should almost certainly not be using this environment to begin with.
-
Thanks, I didn't know about the
gather
environment - that's the functionality I was looking for. – tparker May 2 '16 at 5:58
&
is right aligned towards the alignment point the part after the&
is left aligned. that's how the alignment works. You have a display with only the left hand side of each row. – David Carlisle May 1 '16 at 8:36