match t with
| T_Leaf None => OK []
| T_Leaf (Some (ac,extyvars,coervars,exprvars,ebranch)) =>
mkStrongAltConPlusJunk' tc ac >>= fun sac =>
list2vecOrFail (map (fun ev:WeakExprVar => ev:CoreVar) exprvars) _ (fun _ _ => "WECase")
>>= fun exprvars' =>
match t with
| T_Leaf None => OK []
| T_Leaf (Some (ac,extyvars,coervars,exprvars,ebranch)) =>
mkStrongAltConPlusJunk' tc ac >>= fun sac =>
list2vecOrFail (map (fun ev:WeakExprVar => ev:CoreVar) exprvars) _ (fun _ _ => "WECase")
>>= fun exprvars' =>