Display, centered or not, of the following aligned list
$al = new_aligned_list(ans_rule_len=>15, spacing=>'5', tex_spacing=>'5 pt');
$al -> qa(
'amplitude $SPACE' , $AMP -> cmp() ,
'period' , $PER -> cmp() ,
shows same-width spacing around = for the first line but not the second:
amplitude = [box]
Although coding is cleaner for the second line, I have been using the first line's hack because no value for the spacing parameter has given the prettier display. Are there alternative ways to get same-width spacing around =?