multiple if scenarios

How can I formulate the following 3 scenarios: 

Assuming j9 cannot be yes if k9 is vacant AND my current tab is "Feb" and previous tab is "Jan", how do I formulate the following: 

if k9 = "VACANT", i9 should equal zero 

if j9 = "Yes", i9 should equal f9-g9

if k9 is not "VACANT" and j9 = "No", I need i9 to equal my previous tab's i9-h9

If I use =IF(J9="Yes",F9-G9,Jan!i9-H9), this doesn't consider k9 as "VACANT"

If I use =IF(K9="VACANT",0,Jani9-H9), this doesn't consider j9 as "Yes"

How do I combined these?