What is a Miniscript fragment? And what should I call the underscore letter?

Question

An example Miniscript is:

and_v(or_c(pk(B),or_c(pk(C),v:older(1000))),pk(A))

(Generated using this Miniscript site).

What would a fragment be here? What should I call the underscore letter (_v)? And the (v:)?

Answer 1

What would a fragment be defined as here?

The functions in Miniscript (e.g. and_v, older(1000)) are referred to as fragments.

What should I call the underscore letter (_v)?

and_v is the fragment and the _v part of it is the suffix.

And the (v:)?

The v: in v:older(1000) is a wrapper.

Some additional definitions may be of interest.

We use the term valid for any correctly typed Miniscript. And we use the term safe for any sane Miniscript, ie one whose satisfaction isn't malleable, which requires a key for any spending path, etc.

Thanks to individuals for answering this on IRC.