function t.nan(V)if V~=V then return true else return false,"\117\110\101\120\112\101\099\116\101\100 \110\111\110-\078\097\078 \118\097\108\117\101"end end

function t.nan(value)
	if value ~= value then
		return true
	else
		return false, "unexpected non-NaN value"
	end
end
