Column Validation AND OR - Prevent Save

Question

I have a SharePoint list with Column Status and Impact. I need to validate If Status equals "Pending" or "Approved", then Impact can NOT equal "U". At this point I want the users to change their choice for Impact to "Y" or "N" otherwise they can not save.

Column (dropdown) Name:

Status - New, Pending, Pending Assessment, Approved

Impact - U, Y, N

I've attempted the following Formulas: but they don't seem to work correctly

=IF([Status]="Approved" or "Pending Assessment",AND(NOT([Impact]="U")),FALSE)

=OR([Status]="Approved" , [Status]="Pending Assessment"),AND([Impact]="U"),FALSE)

=IF(ISNUMBER(FIND("Approved",[Status])),AND(NOT([Impact]="U")),FALSE)

Answer 1

Try below formula:

=IF(OR([Status]="Approved", [Status]="Pending"),IF([Impact]="U",false, true), true) 

Update from comments:

=IF(OR([Processing State of CS]="Approved for Implementation",[Processing State of CS]="Approved for Assessment"),IF(OR([CAT Impact]="U",[SEC 31 Fee]="U"),FALSE,TRUE),TRUE)