Hendrycks Math extraction rule seems too strict

[fzyzcjy]

Hi thanks for the library! It seems that the way how math answer is extracted, i.e.

lm-evaluation-harness/lm_eval/tasks/hendrycks_math/utils.py

Lines 20 to 24 in bcb4cbf

	indices = [pos for pos, char in enumerate(results[0]) if char == "$"]
	if len(indices) <= 1:
	answer = results[0]
	else:
	answer = results[0][indices[0] + 1 : indices[-1]]

, may be too strict.

For example, the following answer: ... some reasoning logic ... Thus the answer is \[ \boxed{42} \] is not extracted, because it is not a $.

[baberabb]

Hi! This is based on the original code, but we can add another metric to show alongside by adding a flexible-extract filter, as gsm8k does it. PR welcome!