🚀 go-pugleaf

Many thanks to the respondents of my query on how to get tex to output

( x y z ) ( a b c )
          ( d e f )
          ( g h i )

Two solutions presented themselves. One due to Donald Arseneau who
did it "right" by modifying TeX's matrix code. See the his posting.

The "slick and quick" solution is as follows:

this is another method using vphantoms (boo!):
$$
\matrix{ \vec x= \cr
   \vphantom{ 0 } \cr
   \vphantom{ 0 } \cr}
\matrix{ \pmatrix{a & b & c\cr} \cr
   \vphantom{ 0 } \cr
   \vphantom{ 0 } \cr}
\pmatrix{ 1 & 0 & 0 \cr
   0 & 1 & 0 \cr
   0 & 0 & 1 \cr}
$$
and this solution is due to Bruce Ikenaga of Case Western
\bye

Possibly, one should use \mathstrut's instead of the \vphantom's.
Also, the later method actually does a better job of aligning the rows.