const multiply = (a) => (b) => (c) => a * b * c;

const step1 = multiply(2);
const step2 = step1(3);
const result1 = step2(4);

const result2 = multiply(2)(3)(4);

const partialMultiply = multiply(5);
const result3 = partialMultiply(2)(3);

const doubler = multiply(2)(1);
const result4 = doubler(7);

console.log(result1, result2, result3, result4);