How to add line feed and tag?

[suda-morris]

1. \tag{1} can not be rendered
2. How to align multiple lines in formula? I tried \\ but it doesn't take effect.

[suda-morris]

any updates?

[shigma]

It seems a mathjax3 issue.

[c0mm4nd]

Please add multiple lines support, thanks.

[c0mm4nd]

$$\displaylines{line1\\line2\\line3}$$

[c0mm4nd]

$$f(x)=test_1 \tag{1}$$

All passed under #35