; -*- Scheme -*-
;
; $Id: string06.scm,v 1.1 1998/03/16 07:59:33 foner Exp $

; type Scheme-String = Char-seq
;
; A Scheme-String is a sequence of characters that have the same indexing
; properties as Scheme strings.
;
; Since Scheme is 0 based and VDM is 1 based this means 1 has to be
; added to each index :-
;
; _ [ _ ] : Scheme-String x Z -> Char
; l[i] = l[i+1]
;
; A substring in Scheme has an inclusive lower bound but an exclusive
; upper bound and so it is not necessary to alter the upper bound :-
;
; _ ( _ .. _ ) : Scheme-String x Z x Z -> Scheme-String
; l(i .. j) = l(i+1 .. j)
;
; All the other usual sequence operations are similarly extended to
; Scheme strings.

