New posts in Chain Rule

Why is this famous proof of the chain rule called "technically incorrect" in this pdf?

What's my confusion with the chain rule? (Differentiating $x^x$)

Why is there only one term on the RHS of this chain rule with partial derivatives?

Why can you mix Partial Derivatives with Ordinary Derivatives in the Chain Rule?

Derivation of the multivariate chain rule

Why is the following NOT a proof of The Chain Rule?

Chain Rule Intuition