f_sub             133 complex.c      f_sub(VALUE x, VALUE y)
f_sub              33 ext/date/date_core.c #define f_sub(x,y) rb_funcall(x, '-', 1, y)
f_sub              16 ext/date/date_parse.c #define f_sub(x,y) rb_funcall(x, '-', 1, y)
f_sub              40 ext/date/date_strptime.c #define f_sub(x,y) rb_funcall(x, '-', 1, y)
f_sub             128 rational.c     f_sub(VALUE x, VALUE y)