#import "@preview/fletcher:0.6.0" as fletcher: diagram, node, edge

#let hom = edge.with(in-math: true)
#diagram(
$
A hom(->, f) hom("d", ->, g) & X hom("d", ->, iota_Y, #right) \
Y hom(->, iota_X, #bottom) & X +_A Y
$,
// for a pushout, use a `corner` mark
// and a blank ` ` line style
edge((0,0), (1,1), " corner", outset: 5pt)
)