Re: @displaymath \leqalignno problem for pdf output

[Gavin Smith]

On Fri, Nov 13, 2020 at 08:34:56PM +0000, Gavin Smith wrote:
> On Thu, Nov 12, 2020 at 11:23:33PM +0100, Christopher Dimech wrote:
> > A small thing that can be a quick fix is that @displaymath introduces
> > excessive vertical spacing when using \displaylines in pdf output.  The
> > output is good for html.
> 
> I can confirm this but don't have a quick fix for it.  I will have to
> delve into the definition of \displayline

This happens with plain TeX too, as can be seen with the following input:

f

$$\displaylines{a+b}$$

f

$$a+b$$


\bye


There is more vertical space above the first display than above the second.