question: What did Frédéric introduce Liszt as in when referring to him in his letters up to 1848 ?
answer: my friend Liszt
turker_answer: Frederic introduced Liszt as `` my friend Liszt '' when referring to him in his letters up to 1848 .
rule-based: Frédéric introduced my friend Liszt Liszt as in when referring to him in his letters up to 1848 .