%!PS

% begin included library code
% see https://codeberg.org/Firedrake/postscript-libraries/
/enumerate.array {
    1 dict begin
    /a exch def
    [
      0 1 a length 1 sub {
          [ exch dup a exch get ]
      } for
    ]
    end
} bind def

/test.end {
    ( ) print
    test.count 0 gt {
        (Passed ) print
        test.pass (...) cvs print
        (/) print
        test.count (...) cvs print
        ( \() print
        test.pass 100 mul test.count idiv (...) cvs print
        (%\)) print
        (\r\n) print
    } if
} bind def

/test.start {
    print (:) print
    /test.pass 0 def
    /test.count 0 def
} bind def

/test {
    /test.count test.count 1 add def
    {
        /test.pass test.pass 1 add def
    } {
        ( ) print
        test.count (....) cvs print
        (-fail) print
    } ifelse
} bind def


% end included library code

/xmatrix {
    0 dict begin
    dup length 1 sub /order exch def
    /valid true def
    enumerate.array {
        aload pop
        exch
        /y exch def
        enumerate.array {
            aload pop
            /value exch def
            /x exch def
            x y eq x order y sub eq or {
                value 0 eq {
                    /valid false def
                } if
            } {
                value 0 ne {
                    /valid false def
                } if
            } ifelse
            valid not {
                exit
            } if
        } forall
        valid not {
            exit
        } if
    } forall
    valid
    end
} bind def

(xmatrix) test.start
[[1 0 0 2] [0 3 4 0] [0 5 6 0] [7 0 0 1]] xmatrix test
[[1 2 3] [4 5 6] [7 8 9]] xmatrix not test
[[1 0 2] [0 3 0] [4 0 5]] xmatrix test
test.end