a__zeros cons 0 zeros a__and tt X mark X a__length nil 0 a__length cons N L s a__length mark L mark zeros a__zeros mark and X1 X2 a__and mark X1 X2 mark length X a__length mark X mark cons X1 X2 cons mark X1 X2 mark 0 0 mark tt tt mark nil nil mark s X s mark X a__zeros zeros a__and X1 X2 and X1 X2 a__length X length X 2.2 mark and X1 X2 a__and mark X1 X2 mark length X mark X a__length cons N L a__length mark L mark zeros a__zeros a__length cons N L mark L mark length X a__length mark X mark and X1 X2 mark X1 a__and tt X mark X mark cons X1 X2 mark X1 mark s X mark X true mark s X mark X mark cons X1 X2 mark X1 a__and tt X mark X mark and X1 X2 mark X1 a__length cons N L a__length mark L mark length X mark X mark length X a__length mark X a__length cons N L mark L mark and X1 X2 a__and mark X1 X2 true s 1 1 0 and 2 1 2 2 zeros 0 1 mark 1 1 0 0 0 0 a__and 2 2 1 a__zeros 0 0 nil 0 36466 mark 1 1 1143 a__length 1 1 9308 cons 2 1 2 1143 tt 0 38139 a__and 2 1 2 2 length 1 1 10452 a__zeros 0 1144 a__length 1 1 10452 a__length cons N L a__length mark L mark s X mark X a__length cons N L s a__length mark L a__length X length X mark cons X1 X2 cons mark X1 X2 a__zeros cons 0 zeros a__length nil 0 mark zeros a__zeros mark tt tt mark length X a__length mark X a__and X1 X2 and X1 X2 mark s X s mark X mark nil nil mark 0 0 a__zeros zeros mark and X1 X2 a__and mark X1 X2 a__and tt X mark X a__length cons N L a__length mark L true Failed! NaTT certifiable-1.6