( ( ( ( ( It ( is ( used ( ( ( with ( ( annotations types ) ( containing ( only ( one element ) ) ) ) ) or ) ( in ( ( the case ) ( when ( ( multiple elements ) ( are present ) ) ) ) ) ) ) ) ) , ) but ) ( ( only ( one elements ) ) ( lacks ( a ( default value ) ) ) ) ) . )
(ROOT (S (S (NP (PRP It)) (VP (VBZ is) (VP (VBN used) (PP (PP (IN with) (NP (NP (JJ annotations) (NNS types)) (VP (VBG containing) (NP (RB only) (CD one) (NN element))))) (CC or) (PP (IN in) (NP (NP (DT the) (NN case)) (SBAR (WHADVP (WRB when)) (S (NP (JJ multiple) (NNS elements)) (VP (VBP are) (ADJP (JJ present))))))))))) (, ,) (CC but) (S (NP (RB only) (CD one) (NNS elements)) (VP (VBZ lacks) (NP (DT a) (NN default) (NN value)))) (. .)))
It is used with annotations types containing only one element or in the case when multiple elements are present, but only one elements lacks a default value.
(ROOT (S (NP (PRP You)) (VP (VBP call) (NP (NP (NNS elements)) (SBAR (WHNP (WDT that)) (S (VP (VBP contain) (NP (NP (JJ only) (NNS atoms)) (PP (IN of) (NP (NP (CD one) (NN type)) (PP (IN of) (NP (NN element) (NN native) (NNS elements))))))))))) (. .)))