Array Types  63  Produces as results (assuming appropriate input):  6.B.  String Types  where array variable  A  and expression  E  have any string types with the  same number of components is valid. Similarly, the relational operators  (=, <>, <, >,  <=, and <=) may be used to compare any two strings that  have the same number of components; the ordering considers the first  Such a type is called a  string type.  The assignment  A  :=  E  Strings  were defined earlier  as sequences of characters enclosed in  apostrophes (Section I.E). Strings consisting of a single character are  the constants of the standard type  Char  (Section 2.D); those of N  characters  (N  >  1),  are constants of a type defined by:  packed array  [1 .. N]  of Char  Note that the index types for arrays A, B, and C in the above program  are fixed.  If  we could write a generalized matrix-multiply subprogram  for a library, we need a facility to provide for adjustable index types.  Pascal provides conform ant-array parameters for this purpose (see  Section 11.A.2); and Program 11.4, MatrixMul2, illustrates their use.  1  2  3  -2  0  2  1  0  1  -1  2  -3  -1  3  -2  2  2  1  1  10  6  -4  1  4  -9  -2 