elim (tweq_dec U1 U2) [ #HpU12 | -HTU2 #HnU12 ]
[ @(ex2_intro … T2) (**) (* full auto not tried *)
[ /3 width=6 by cpms_zeta, cpms_step_sn, cpm_bind/
elim (tweq_dec U1 U2) [ #HpU12 | -HTU2 #HnU12 ]
[ @(ex2_intro … T2) (**) (* full auto not tried *)
[ /3 width=6 by cpms_zeta, cpms_step_sn, cpm_bind/