src/sage/rings/convert/mpfi.pyx: Use sage.rings.abc

src/sage/rings/convert/mpfi.pyx

@@ -20,10 +20,10 @@ from sage.libs.mpfi cimport *
 from sage.arith.long cimport integer_check_long
 from sage.cpython.string cimport bytes_to_str
 from sage.structure.element cimport Element, parent
+import sage.rings.abc
 from ..integer cimport Integer
 from ..rational cimport Rational
 from ..real_mpfi cimport RealIntervalFieldElement, RealIntervalField_class
-from ..complex_interval_field import ComplexIntervalField_class
 from ..real_mpfr cimport RealNumber
 from ..real_double cimport RealDoubleElement
 from ..complex_mpfr cimport ComplexNumber
@@ -188,7 +188,7 @@ cdef int mpfi_set_sage(mpfi_ptr re, mpfi_ptr im, x, field, int base) except -1:
         except AttributeError:
             pass
         else:
-            if not isinstance(field, ComplexIntervalField_class):
+            if not isinstance(field, sage.rings.abc.ComplexIntervalField):
                 field = field.complex_field()
             e = <ComplexIntervalFieldElement?>m(field)
             mpfi_swap(re, e.__re)