intuition.
eapply leRat_trans.
2:{
eapply (@evalDist_sum_le_1 _ c).
}
pose proof (comp_EqDec c).
destruct (in_dec (EqDec_dec _) a (getSupport c)).
eapply leRat_trans.
2:{
eapply eqRat_impl_leRat.
symmetry.
rewrite (sumList_partition (eqb a)).
eapply ratAdd_eqRat_compat.
eapply sumList_exactly_one.
eapply getSupport_NoDup.
eauto.
intuition.
case_eq (eqb a b); intuition.
exfalso.
eapply H1.
eapply eqb_leibniz.
trivial.
eapply ratMult_0_r.
eapply eqRat_refl.
}
eapply leRat_trans.
eapply eqRat_impl_leRat.
eapply ratAdd_0_r.
eapply ratAdd_leRat_compat.
rewrite eqb_refl.
eapply leRat_trans.
2:{
eapply eqRat_impl_leRat.
symmetry.
eapply ratMult_1_r.
}
intuition.
eapply rat0_le_all.
apply getSupport_not_In_evalDist in n.
rewrite n.
eapply rat0_le_all.
Qed.

Theorem evalDist_complement :
forall (c : Comp bool),
well_formed_comp c ->
evalDist c false == ratSubtract 1 (Pr[c]).