The two programs are currently housed in buildings about a block apart.
( ( The ( two programs ) ) ( ( ( are currently ) ( ( housed ( in ( buildings ( about ( a block ) ) ) ) ) apart ) ) . ) )
(ROOT (S (NP (DT The) (CD two) (NNS programs)) (VP (VBP are) (ADVP (RB currently)) (VP (VBN housed) (PP (IN in) (NP (NP (NNS buildings)) (PP (IN about) (NP (DT a) (NN block))))) (ADVP (RB apart)))) (. .)))
The reason for the programs' close proximity to each other is the similarities of their programs.
( ( ( The reason ) ( for ( ( ( the ( programs ' ) ) ( close proximity ) ) ( to ( each other ) ) ) ) ) ( ( is ( ( the similarities ) ( of ( their programs ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NN reason)) (PP (IN for) (NP (NP (NP (DT the) (NNS programs) (POS ')) (JJ close) (NN proximity)) (PP (TO to) (NP (DT each) (JJ other)))))) (VP (VBZ is) (NP (NP (DT the) (NNS similarities)) (PP (IN of) (NP (PRP$ their) (NNS programs))))) (. .)))