Re: [Groff] RE: eqn matrix?

[Werner LEMBERG]

> Yes, that must be it. In my file, I replaced the space in
> 
> matrix {
> 
> with a tab, and eqn did not like it! (Same message as you got).  But
> now, like you, I'm puzzled that it should be seen as a problem.

This is correct behaviour (and Gunnar's eqn behaves as groff's eqn).

To cite `A System for Typesetting Mathematics' from Kernighan and
Cherry:

  Input is free-form.  Spaces and new lines in the input are used by
  EQN to separate pieces of the input; they are not used to create
  space in the output.  Thus

    x   = y
       +z+1

  also gives x = y + z + 1.  Free-form input is easier to type
  initially; subsequent editing is also easier, for an expression may
  be typed as many short lines.

  Extra white space can be forced into the output by several
  characters of various sizes.  A tilde ‘‘~’’ gives a space equal to
  the normal word spacing in text; a circumflex gives half this much,
  and a tab character spaces to the next tab stop.

And in `Typesetting Mathematics -- User's Guide' you can find this
additional information:

  Tabs may also be used to position pieces of an expression, but the
  tab stops must be set by TROFF commands.

With other words: At those places where you can put a `~' you can also
put a tab character to get an *optical effect* in the eqn output.  You
can't use it to format the eqn input data.


    Werner