Option to make individual aligned equations flush left like flalign

[tyilo]

Is your feature request related to a problem? Please describe.
I would like to align equations, but not have them centered, but "flushed" left like the flalign environment.
I doesn't seem like the provided aligned environment supports this.

Describe the solution you'd like:
Maybe provide a flaligned environment?

Link to or name of a (La)TeX package that provides the same feature:
flalign from amsmath

Describe alternatives you've considered:
I haven't found any alternatives that can do this.

Additional context:

[edemaine]

Do you want all equations flushed left? We recently added the fleqn option that does this (named after a \documentclass option supported by base LaTeX), and hopefully that's exactly what you want.

If you need a mixture of flushed left and centered... that should of course be possible, but I'm not sure what the right interface would be. flaligned environment would be too late (equation is already centered).

[tyilo]

Actually I want both ;)

[alexlenail]

I too would like this. I'd like to interleave left-justified \text{explanations} among \begin{aligned} equations.

What I have now:

[edemaine]

@alexlenail Does the fleqn option do what you need? (It's equivalent to the \documentclass option supported by base LaTeX, flushing all equations left.)

[alexlenail]

@edemaine it's possible, but that's a global option (rather than in the tex) right? What if I want most of my equations centered, just not this one?

(Unrelated: in the image above, you might notice the red \right)'s. That seems to have changed spontaneously a few days ago. I asked on SO).

[edemaine]

Fair enough. And I realize now that amsmath provides the flalign environment expressly for this (as mentioned by the original poster). Luckily, we now support top-level math environments like align, so this is actually possible now (unlike in 2019 when this was first raised). So the interface is clear now; just a matter of someone implementing it.

(For unrelated issues, please open a separate issue. The interaction between \color and \right changed within the past few months, but it should have been to fix bugs like that, not introduce them.)

[alexlenail]

Just to clarify: extending the explanatory text to span the width of the equation in my picture above is not currently possible, but would be with flalign, which just needs to be implemented? I think I initially misread your comment and thought I could achieve this with {align} but could not.

[SkytAsul]

Would be nice to see after so long :)

[Reader-404]

Hey.
So, I need some help with this. I want both text & equations in KaTex to be aligned left. I am not certain what I am supposed to do with fleqn to achieve this.