def abs(self, o, df):
f, = o.ufl_operands
# return conditional(eq(f, 0), 0, Product(sign(f), df)) abs is
# not complex differentiable, so we workaround the case of a
# real F in complex mode by defensively casting to real inside
# the sign.
return sign(Real(f)) * df
def real(self, o, df):
return Real(df)