Subject	concave lens
Predicate	form
Object	virtual image
Modality	Modality Occurrences always 3 TBC[virtual image of object] 1
Polarity	POSITIVE
Plausibility	0.6134
Neighborhood Sigma	0.6135
Local Sigma	0.6996
Example Sentences	Sentence Occurrences Source concave lenses always form virtual images 2 Google Autocomplete a concave lens always forms a virtual image of an object 1 Google Autocomplete