Which of the listed import statements are identical?

Question

I have identified the following import statements in node. Do all the statements below import mathgraph with a different namespace scope, or which import styles are identical?

const/var/let mathgraph = require('mathgraph');

import * as mathgraph from 'mathgraph';
import mathgraph from 'mathgraph';
import { mathgraph } from 'mathgraph';
import mathgraph = require('mathgraph');