A YouTube video (https://www.youtube.com/watch?v=6SzZ_jAHasE) asked what was the answer to this type of fraction:
$$\dfrac {1+1+1+1+1+1}{\dfrac {1+1+1+1+1}{\dfrac {1+1+1+1}{\dfrac{1+1+1}{\dfrac{1+1}{1}}}}}\\$$
I had thought that this was equivalent to division, and hence:
$$6 / 5 / 4 / 3 / 2 / 1 = \frac{1}{20}$$
evaluating from left to right.
However, the solution appeared to start the evaluation of the fraction at the bottom.
Is there a defined rule for this? (Note: "no" would be an acceptable answer).
The size of the horizontal lines distinguish this: $$\dfrac a{\dfrac bc}\text{ refers to }a/(b/c).$$ $$\dfrac{\dfrac ab}c\text{ refers to }(a/b)/c.$$ That said, you should never write like this.