How can I interpret "if not 1+1 ==y or x==4 and 7==8"

Question

How can I interpret "if not 1+1 ==y or x==4 and 7==8"

- doesn't it mean that if either of "1+1==y" and "x==4 and 7==8" is false?

Answer 1

No, they should be in parenthesis to do that. ("not" changes only the first statement)

Simplified:

if 1+1!=y or x==4 and false

=>

if 1+1!=y

=>

if y!=2==true

Answer 2

this is the explanation:
x = 4
y = 7

not 1+1 ==y or x==4 and 7==8

so lets elaborate,
(not 1+1==y ) //--> not 2 == 7 //--> not false // TRUE <-- answer on the first problem
=>
(X == 4) //--> 4 == 4 //--> TRUE <-- answer on the second problem
=>
(7==8) //--> FALSE <-- answer on the third problem

lets combine all.
(TRUE or TRUE) and FALSE //--> TRUE or TRUE is TRUE
=>
TRUE and FALSE is FALSE

so the answer is False,