( ( ( a halo ) ( inside ( ( the ( main ring ) ) ( shaped ( like ( a ( double-convex lens ) ) ) ) ) ) ) ; )
(ROOT (NP (NP (NP (DT a) (NN halo)) (PP (IN inside) (NP (NP (DT the) (JJ main) (NN ring)) (VP (VBN shaped) (PP (IN like) (NP (DT a) (JJ double-convex) (NN lens))))))) (: ;)))
a halo inside the main ring shaped like a double-convex lens;
(ROOT (S (NP (DT The) (ADJP (RBS most) (JJ common)) (JJ two-lens) (NN telescope)) (, ,) (PP (IN like) (NP (DT the) (JJ simple) (NN microscope))) (, ,) (VP (VBZ uses) (NP (NN convex) (NNS lenses))) (. .)))