In this task, you're given a pair of sentences, sentence 1 and sentence 2. Your job is to determine if the two sentences clearly agree/disagree with each other, or if this can't be determined. Indicate your answer as yes or no respectively.
Q: Sentence 1: In 1839, the governor of Singapore sent James Brooke (1803 1868) to promote trade links with the Sultan of Brunei. Sentence 2: James Brooke undertook his trading mission on his own.
A: 
yes