Task: Text Simplification
Input (English): he was involved in litigation in 1889 with his former assistant charles a. borst , and the " great star-catalog case " peters v. borst went before the supreme court of new york.
Output (English): he was involved in legal action in 1889 with his ex-assistant charles a. borst , and the " great star-catalog case " peters v. borst went before the supreme court of new york.