> (mapOptionTree weakLT' pcb_freevars),,(unleaves (map (fun t => t@@weakL' lev)
(vec2list (sac_types sac Γ avars))))
|- [weakLT' (branchtype @@ lev)]
> (mapOptionTree weakLT' pcb_freevars),,(unleaves (map (fun t => t@@weakL' lev)
(vec2list (sac_types sac Γ avars))))
|- [weakLT' (branchtype @@ lev)]