Would anyone be willing to explain to me what is happening in this image? I am having trouble unders...

# getting-started

[Gavin Ray]

Would anyone be willing to explain to me what is happening in this image?
I am having trouble understanding the type signature (never seen one like this before) and why it won't accept the value as a valid type

and((MutableCollection<out Condition!>..Collection<Condition!>?))

I think this means "A type with a lower-bounds of MutableCollection<out Condition!> and an upper-bounds of `Collection<Condition!>?`"
But if that is true, then explicitly casting to either of those should have made it work, which it doesn't (as you see in the image) 🤔 😕

[Carlos Ballesteros (InVideo)]

have you tried, val x: MutableCollection<Condition> ?

[phldavies]

Or return add(*conds.toTypedArray())

[Gavin Ray]

casting to varargs and typed array does work, but just confused why trying to return a Collection or MutableCollection doesn't