Advance formula field nested condition not working

Question

I want a formula like this:

IF (
    (Field1 = 'Value1' AND Field2 = 'Value2')
    OR
    ( NOT (ISBLANK (Field3)))
), 
"Output1", "Output2")

This is my actual formula:

IF( 
    (FON_Membership_Status_Formula__c  = 'Active'  &&  FON_Membership_Entity__c  = 'Account')
      OR( NOT( ISBLANK(Parent_Membership__c) ) ) 
, "Member", "Non-Member")

When I check the syntax, it gives the following error:

Error: Syntax error. Missing ')'

I don't know where should I put the missing ')'. Please help.

Answer 1

What about...

IF(
  OR(
    AND(
      FON_Membership_Status_Formula__c  = 'Active',
      FON_Membership_Entity__c  = 'Account'
    ),
    NOT(ISBLANK(Parent_Membership__c))
  ),
  "Member",
  "Non-Member"
)

Answer 2

I changed the formula to something like this and it seems to be working now:

IF(
   AND
   (
   FON_Membership_Status_Formula__c = 'Active' && FON_Membership_Entity__c = 'Account'
   )
   || NOT( ISBLANK(Parent_Membership__c ) )
   
   ,"Member", "Non-Member")