Assertion: lens's number | /r/HasProperty | combined as a compound lens
Facets:
value: in a tube
type: LOCATION
value: to permit the correction of aberrations
type: PURPOSE
value: more often
type: DEGREE
value: together
type: MANNER
Source sentences:
text: More often a number of lenses made of different materials are combined together as a compound lens in a tube to permit the correction of aberrations .