/******************************************************/
/* This is an external procedure called by MAININVT.  */
/******************************************************/
invert:
    procedure (a,r,c);
    %include 'matsize.lib';
    declare 
        (d, a(maxrow,maxcol)) float binary(24),
        (i,j,k,l,r,c) fixed binary(6);
    do i = 1 to r;
       d = a(i,1);
       do j = 1 to c - 1;
          a(i,j) = a(i,j+1)/d;
       end;
       a(i,c) = 1/d;
       do k = 1 to r;
          if k ^= i then
             do;
               d = a(k,1);
               do l = 1 to c - 1;
                  a(k,l) = a(k,l+1) - a(i,l) * d;
               end;
               a(k,c) = - a(i,c) * d;
             end;
       end;
    end;

end invert;