def section(self):
r"""
Return the inverse map of this isomorphism.
EXAMPLES::
sage: K = QQ['x'].fraction_field()
sage: L = K.function_field()
sage: f = K.coerce_map_from(L)
sage: f.section()
Isomorphism:
From: Fraction Field of Univariate Polynomial Ring in x over Rational Field
To: Rational function field in x over Rational Field
"""
from sage.categories.all import Hom
parent = Hom(self.codomain(), self.domain())
return parent.__make_element_class__(FractionFieldToFunctionField)(parent.domain(), parent.codomain())
