// results after subsituting a number for the integration variable.
if (is_exactly_a<numeric>(ea) && is_exactly_a<numeric>(eb)
&& is_exactly_a<numeric>(ef.subs(x==12.34).evalf())) {
// results after subsituting a number for the integration variable.
if (is_exactly_a<numeric>(ea) && is_exactly_a<numeric>(eb)
&& is_exactly_a<numeric>(ef.subs(x==12.34).evalf())) {