Why do most programming languages only have binary equality comparison operators?

Question

In natural languages, we would say \"some color is a primary color if the color is red, blue, or yellow.\"

In every programming language I\'ve seen, that translates

Answer 1

Two possibilities

Java

boolean isPrimary = Arrays.asList("red", "blue", "yellow").contains(someColor);

Python

a = 1500
if  1 < a < 10 or  1000 < a < 2000:
     print "In range"