%!PS

% begin included library code
% see https://codeberg.org/Firedrake/postscript-libraries/
/test.start {
    print (:) print
    /test.pass 0 def
    /test.count 0 def
} 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 {
    /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

/linearrecurrencesecondorder {
    0 dict begin
    /seq exch def
    /a seq 0 3 getinterval def
    /b seq 1 3 getinterval def
    /c seq 2 3 getinterval def
    /q
    b 2 get a 0 get mul b 0 get a 2 get mul sub
    b 1 get a 0 get mul b 0 get a 1 get mul sub idiv
    def
    /p a 2 get a 1 get q mul sub a 0 get idiv def
    p a 0 get mul q a 1 get mul add a 2 get eq
    p b 0 get mul q b 1 get mul add b 2 get eq and
    p c 0 get mul q c 1 get mul add c 2 get eq and
    end
} bind def

(linearrecurrencesecondorder) test.start
[1 1 2 3 5] linearrecurrencesecondorder test
[4 2 4 5 7] linearrecurrencesecondorder not test
[4 1 2 -3 8] linearrecurrencesecondorder test
test.end