## {d a} instead of {curl a} in formulation

Hello,

Regarding a simple understanding question: Magnetostatic formulation is usually given using the following elements:

`FunctionSpace { {Name Hcurl_a_3D ; Type Form1 ; ... `

`Formulation { Name MagStaDyn_av_js_3D ; Type FemEquation ; Quantity { { Name a ; Type Local ; NameOfSpace Hcurl_a_3D ; } ...}`

`Equation { Galerkin { [ nu[{d a}] * Dof{d a} , {d a} ] ; In Domain ; Jacobian Vol ; Integration II ; } ...`

May I ask why `b=curl a`

is called by `{d a}`

instead of `{curl a}`

?

I understand that `{d a}`

is the external derivative and is equivalent to `{Grad a}`

.

Is it that `a`

is not the magnetic vector potential but the scalar potential for the magnetic (vector) field. `b = curl A`

holds but the relevant quantity is `b = grad a`

?

Thanks!

Update - seems like as `a`

is defined as a form1, a curl conform field, `d`

is applied and should equivalent to `curl`

- to be validated?