An exact proof term for the current goal is CD_exp_nat_2 {2} SNo complex_tag_fresh minus_SNo conj add_SNo mul_SNo SNo_0 SNo_1 minus_SNo_0 (λq H ⇒ H) (λq H ⇒ H) add_SNo_0L add_SNo_0R mul_SNo_zeroL mul_SNo_oneR.