(S (S (PP (VBG According) (PP (TO to) (BASENP (DT the) (NNP BBC)))) (COMMA ,) (S (BASENP (NNP Pakistan)) (VP (VBD had) (VP (VBN been) (ADJP (ADJP (JJ unable) (S (VP (TO to) (VP (VB provide) (NP (BASENP (JJ tangible) (NN evidence)) (PP (IN of) (BASENP (PRPD his) (NN death)))))))) (PP (IN because) (PP (IN of) (NP (NP (DT the) (QT (DQL ``) (BASENP (ADJP (JJ remote) (CC and) (JJ hostile)) (NN terrain)) (DQR ''))) (PP (IN of) (BASENP (NNP South) (NNP Waziristan))))))))))) (PERIOD .))