Assertion: skater | /r/CapableOf | perform air
Facets:
value: on vertical ramps
type: LOCATION
Source sentences:
text: The invention of the no-hands aerial (later known as the ollie) by Alan Gelfand in Florida in 1976, and the almost parallel development of the grabbed aerial by George Orton and Tony Alva in California, made it possible for skaters to perform airs on vertical ramps.