Icosohedron's channel

@nancejo It is called the "Carter Scratch"

This song was written by Rowland Salley.

Prine covered it on his "Pink Cadillac" album.

@VeritySeeker "Then" is part of an implication ( p -> q ).

Defining a "set" as a "collection" is not helpful.

But for what you are doing here, as you say, you don't want to worry about the definition of set, and just leave as undefined term.