Results 2 issues of Pieter Belmans

In #158 a customization to strip `{` and `}` from fields was introduced. The problem with the greedy approach in the current implementation is that it will also replace curly...

bug

When parsing the example ``` $$ \xymatrixcolsep{4pc} \xymatrix{ (w'', a'', b'', \phi'') \rtwocell^{(k'_1, \alpha'_1, \beta'_1)}_{(k'_2, \alpha'_2, \beta'_2)}{\delta'} & (w', a', b', \phi') \rtwocell^{(k_1, \alpha_1, \beta_1)}_{(k_2, \alpha_2, \beta_2)}{\delta} & (w, a,...

enhancement