The phrase "is to" can be substituted by various synonyms depending on the context. It can be replaced by words like "will," "shall," "should," "ought to," or "must" to indicate an obligation or necessity. In a planning or instruction process, words like "intends," "plans," "prepares," or "arranges" can be used to convey a sense of purpose. Alternately, synonyms including "equals," "corresponds," "matches," or "represents" can indicate a relationship between two things. Conversely, words like "implies," "suggests," or "hints" can express a degree of uncertainty or speculation. Overall, the varied synonyms for "is to" allow for more nuanced and specific communication.