if(is_prefixed_partspeechAnnotated($base)){  # wordCache{base} gets filled in.
        unless($tok eq $base){      #$prefixLessFm Mostly, base WILL eq tok, but catch the odd case.
            &equivWord($tok, $base, {atail => $atail})};
        1}
    # If $checkPrefix is false, then we've already stripped a prefix, 
    #  so it can't be an abbreviation, a number or an uncannical form.
    elsif($canon{$tok} and $canon{$tok} ne $tok){ 
        &driveBase($canon{$tok}, {%$Args, checkPrefix=>0});
        &equivWord($tok, $canon{$tok}, {})}
    elsif(($sing) = $tok =~ /(.+)S$/ and $canon{$sing} and $canon{$sing} ne $tok){  # So REQTS => REQT => REQUIREMENT
            &equivWord($tok, $canon{$sing}, {plural=>1})}
    elsif($abbrev{$tok}){    # Not normally invoked, as abbrevs have already been expanded usually.
        &equivWord($tok, $abbrev{$tok}, {abbreviation =>1})}
    elsif((&part_number_p($base) or $atail eq 'PARTNO')){
        # P/N and PN: <partno> get transformed in immediate_transforms; see the improves file
        &baseInscript($tok, {group => 'PARTNO', 
                             root => $tok})}

# etc., etc. etc.