Underarrow & Overarrow

[davidleejy]

Does anyone else think having under- and overarrows (much like under- and overbraces) is a great idea?

Can't help but feel that under- or overbracing on a single symbol (e.g., = symbol) can come off a tad un-aesthetic.

[davidleejy]

Experimented with attach() functions and sharing results. (please ignore minor typographical errors 😆)

Typst Code in screenshot:

*Method 1*: Use attach.

1. Nested attach():

$⋃_(α ∈ Λ)^(\(p\)) O_α attach(=, b: attach(arrow.b, b: #text(size:1.5em)[by Defn 1.2]) ) X - A - B$

2. Single attach():

$⋃_(α ∈ Λ)^(\(p\)) O_α attach(=, b: &arrow.b\ &"by Defn 1.2" ) X - A - B$

There's probably a center alignment that could be added here to help the ↓ be aligned directly under the = symbol.

*Method 2*: Use alignment `&` and newline `\` symbols.

Here the vertical gaps are a bit too wide. =to be aethetically pleasing.

$⋃_(α ∈ Λ)^(\(p\)) O_α &= X - A - B \ 
& arrow.b \
& "by Defn 1.2"$

*Method 3*: Rely on under- and overbraces.

$⋃_(α ∈ Λ)^(\(p\)) O_α underbrace(=,"by Defn 1.2") X - A - B$

[davidleejy]

One package that appears worth trying is PinIt https://github.com/OrangeX4/typst-pinit