((a)) If an employer withdraws from a multiemployer plan in a complete withdrawal or a partial withdrawal, then the employer is liable to the plan in the amount determined under this part to be the withdrawal liability.
((b)) For purposes of subsection (a)—
((1)) The withdrawal liability of an employer to a plan is the amount determined under to be the allocable amount of unfunded vested benefits, adjusted—
((A)) first, by any de minimis reduction applicable under ,
((B)) next, in the case of a partial withdrawal, in accordance with ,
((C)) then, to the extent necessary to reflect the limitation on annual payments under , and
((D)) finally, in accordance with .
((2)) The term “complete withdrawal” means a complete withdrawal described in .
((3)) The term “partial withdrawal” means a partial withdrawal described in .