Use Case: procuring a fixed unit a background ontology

#-- in topic map---------------
   SO2 isa phenomenon
    measured-in: mg/m^3
#-- in F3 ---------------------
@M{ phenomenon => $p }
  < [n] { unit => { $p / measured-in } } >
      

Use Case: wave classification (taxonometric reasoning)

#-- in topic map --------------
  tsunami subclasses wave-form
    low  :  2 m
    high : 10 m
#-- in F3 ---------------------
< value     => n.amplitude,
  intensity => {   // wave-form  [ ./low  <= $value ]
                                 [ $value <= ./high ]
               } >