Great point. A subroutine is essentially assigning a signature (name, args, returns) to a block of code and never having to look into the details of the block o

Great point. A subroutine is essentially assigning a signature (name, args, returns) to a block of code and never having to look into the details of the block of code again. A bad subroutine is a subroutine that hides nothing: all the internals details of the subroutine leak through the signature.