Example of three valued logic in SQL Server

Question

I understand that SQL uses three valued logic but I am having trouble understanding how to use this in practice, especially why TRUE || NULL = True and FA

Answer 1

An example of TRUE || NULL = True would be

declare @x as int = null;
if 1=1 or @x/1=1
    print 'true'

An example of FALSE && NULL = False would be

declare @x as int = null;
if not(1=2 and @x/1=1)
    print 'false'