anchor.diff:        (EQ '+ (CAR Expr))
         (CONSP (CDR Expr))
         (CONSP (CDDR Expr))
  -      (shen.ABSEQUAL 1 (CADDR Expr))
  +      (shen.absequal 1 (CADDR Expr))
         (NULL (CDDDR Expr)))
        (LIST (intern "1+") (shen.optimise-application (CADR Expr))))
   
  
positive.code:       (EQ '- (CAR Expr))
        (CONSP (CDR Expr))
        (CONSP (CDDR Expr))
        (shen.ABSEQUAL 1 (CADDR Expr))
        (NULL (CDDDR Expr)))
       (LIST (intern "1-") (shen.optimise-application (CADR Expr))))
  
  
negative.code:       (CONSP Expr)
        (EQ '+ (CAR Expr))
        (CONSP (CDR Expr))
        (shen.absequal 1 (CADR Expr))
        (CONSP (CDDR Expr))
        (NULL (CDDDR Expr)))
       (LIST (intern "1+") (shen.optimise-application (CADDR Expr))))
  