OK, I thought so.
( OK ( , ( I ( ( thought so ) . ) ) ) )
(ROOT (S (INTJ (UH OK)) (, ,) (NP (PRP I)) (VP (VBD thought) (ADVP (RB so))) (. .)))
Yes, there was virtually no doubt in my mind that that was the case. 
( Yes ( , ( there ( ( ( ( was ( ( virtually no ) doubt ) ) ( in ( my mind ) ) ) ( that ( that ( was ( the case ) ) ) ) ) . ) ) ) )
(ROOT (S (INTJ (UH Yes)) (, ,) (NP (EX there)) (VP (VBD was) (ADVP (RB virtually) (DT no) (NN doubt)) (PP (IN in) (NP (PRP$ my) (NN mind))) (SBAR (IN that) (S (NP (DT that)) (VP (VBD was) (NP (DT the) (NN case)))))) (. .)))