Using a range in Symbolics.jl

I’m playing with Symbolics.jl. I’d like to define a function which sums items over a range, e.g.

@variables a b
sumsq(a, b) = sum(l -> l^2, a:b)
@register sumsq

Reading Frequently Asked Questions · Symbolics.jl makes me think this is impossible, am I right?

Registering this function is fine. You just need to use the right syntax.

@variables a b
sumsq(a, b) = sum(l -> l^2, a:b)
@register_symbolic sumsq(a,b)