Like in video tutorial **Introduction and Monoids**, in this, they discuss about Category Theory and Monoids. But in one example where the instructor pick the example for **merge** operation, where he pick the sample for hash map. According to the instructor, the **merge** operation is **Associative** means change the sequence but the answer is remain same, but I have doubt on it. for example.

Following are **HashMaps**:

hm1 = {a -> 1, b -> 2 }

hm2 = {a -> 10, b -> 20 }

hm3 = {a -> 100, b -> 200 }

If we merge hm1 -> hm2 -> hm3 our results are

{a -> 1, b -> 2} // hm1 overdrives hm2 values and after result overrides hm3 values

If we merge hm3 -> hm2 -> hm1

{a -> 100, b -> 200} // reasons are same above.

So, Please correct me If am wrong. I am picking this example because in the case of commutative, the instructor pick this sample.