is_prime_field is provided by the category Rings now

Author: mantepse

src/sage/combinat/sf/sfa.py

@@ -1877,9 +1877,6 @@ def __init__(self, Sym, basis_name=None, prefix=None, graded=True):
 
     _print_style = 'lex'
 
-    def is_prime_field(self):
-        return False
-
     # Todo: share this with ncsf and over algebras with basis indexed by word-like elements
     def __getitem__(self, c):
         r"""