Sentence:  We note that two such curves C and **f , cannot coincide at more than a finite number of points ; otherwise , being analytic , they would coincide at all points , which <WSD>is</WSD> impossible since they do not coincide near **f . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)