a.js

const ZERO = 0;
const ONE = 1;
const TWO = 2;

/**
 * Checks if a's state satisfies a certain requirement so that the
 * caller function can understand what's happening with a and 
 * process accordingly. 
 */ 
function checkA(a) {
  const isInt = int(a) == a;
  const checkDiv = (a >> ONE) == ONE;
  const checkMod = (a % TWO) == ZERO;

  If (isInt && checkDiv && checkMod) {
      return a == a;
  } else {
      return a != a;
  }
}