if($checkPrefix and   
   $base =  &driveBase($canon{$tok}, {%$Args, checkPrefix=>0})){
    &equivWord($tok, $canon{$tok}, {})}
elsif($checkPrefix and $savbase = &is_measure_physics_frac($tok)){
    $num_item{$tok} = 1;
    &baseInscript($tok, {group => $savbase,
                         num_item =>1, 
                         root => $tok})}
elsif($base =~ /^[a-z,A-Z]$/){
   &baseInscript($tok, {group =>  'LETTER', root => $tok})}