Ah, well, that explains.
But personally I'm with those who take capital = debt + equity.
U may view some liabilities close enough to debt, account payable is a reasonably good example in this way, but there are other liabilities far from semblance to debt, and I think the note gives abundant of those examples, to name one, if u sell a service contract for a year, u got paid for the whole year service, but are obliged to service provision, then that creates a liability, which will materialize to asset or debt thing depending on how the service proceeds, and u may not have full control on whether it realizes to assets or how much of it realizes to assets, e.g., what if your customer change mind and want to break out of the contract.  

不清楚

书上什么地方说total capital = total assets 了？
if i remember correctly, total capital = debt + equity,
total assets = liability + equity,
they equal if your liability only consists of debts, but u may have other liabilities like accounts payable.

在notes里"Financial Analysis Techniques"里“Some analysts consider these liabilities a source of financing for a firm and include them in total capital. Other analysts view total capital as the sum of a firm's debt and equity." "Total capital = total assets" 不知道这和你说的是不是一回事. 谢谢！