Using .2C with TROFF (results received)

[Chris M. Beery]

The following was the little info I received on the question for the output
of tables side by side in a 2 column output.
1)  Keep table width around 4mm (give or take)
2)  Substitute the .2C macro with the following where "a" is a valid unused
    register (I haven't verified this yet).
    .mk a
    .TS
    ...
    .TE
    .sp |\nau
    .in +3i
    .TS
    ...
    .TE
    .in -3i
    .sp |\n(.hu

Should anyone have a better solution, I'm still open for suggestions.
Thanks
att!drutx!cmb