Feb. 18,2021  32  US 2021/0048748 Al  -continued  -continued  [0085]  Examples of the cation in the monomer from which  recurring unit (2) or (f3) is derived are the same as will be  shown later for the cation in the sulfonium salt having  formula (1-1 ).  [0086]  Examples of the anion in the monomer from which  recurring unit (2) is derived are shown below, but not limited  thereto.  RA  is as defined above. 