/sci/ - Science & Math

Guys confused asf by the wording here. What does continuity mean WITH RESPECT TO d_a?

I get that f:(X,dx)->(Y,dy) is continuous if:

for all e>0 there exists a b>0 s.t for all x' in X

dx(x',x)<b implies dy(f(x'),f(x))<e

But what do we mean when it says wrt d_a??

does it mean ||.||_a: (V,da)->(R,da) or what??