Not to beat the dead horse...
I may be wrong in the history, apologies in advance it I am...
The actual cash outlay for VX stock was something like $2.6bn. The other $1.4bn of "debt" (the total of $4.0bn) was calculated off the aircraft lease payments, those payments were covered as VX was cash flow positive/profitable at the time of purchase. In addition, AS gained $600m in cash that VX had on hand.
S