'\bf{\left\{ \begin{array}{l} {a}\\{a} \end{array}\right.}'Cannot render completely

[lhy666]

I hope it's all bold

[lhy666]

I find that if there is a "\ ", there will be problems.

[dpvc]

Actually, none of it should be bold (it true LaTeX, the \bf has no effect on the array), so the first entry should be an italic, non-bold "a" as well.

I find that if there is a "\ ", there will be problems.

Can you be more specific about what problem you are seeing?

[lhy666]

Thank you for your answer. usually,I used to use '\bf' when i need bolding something.
like '\bf a' and '\bf \sqrt{a^2+b^2}'. now I just want to know how to bold '\begin{array}{l} {a}\{a} \end{array}\right.
like:

not:

[lhy666]

Oh, I see. the ' \bf' has no effect on the array, if i want this:

I should write like ‘\left{ \begin{array}{l} \bf{a}\ \bf{a} \end{array}\right.’
thank you very much.