For the following user request in natural language, generate a query that would find the sentences most relevant to the request from a database indexed by lemmatized words. A query is a string containing lowercase lemmatized words, logical operators OR and AND, and parentheses.
User request: "Find phrases that talk about improvement in the cash flow"
Query: cash AND flow AND (improvement OR improve OR better OR increase)
User request: "Find sentences that discuss a company growing its capex"
Query:  Avoid using the following keywords: database, sentence, parenthesis, company
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