> ? [some #electromagnetic_unit]

[pm#graph1_on_electromagnetism
     [any #electromagnetism,
          may have for pm#force_measure: several #electromagnetic_unit]
];

[pm#graph1_on_radiation
     [any #radiation,
          may have for pm#radiation_measure: several #radioactivity_unit]
];

//Search time: 0.00018 s, printing time: 0.0005 s (according to the Unix function gettimeofday())